In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"The Other Harry" wrote in message
...

The question was (and is), what happens to the load?

If the entire pot arrangement weighs 40 pounds, does half
of that load go to the top hook and half of it go to the
anchor hook?

--
Harry

I am assuming you have a rope attached to the pot, that runs up to a
hook
or
pulley attached to the ceiling,, then back down to an cleat.
If the pot weighs 40 lbs, the top hook in the ceiling, (or window
frame,
whatever!) with the pulley will be carrying 80 lbs. The tension,
(weight)
felt by the rope at the cleat will be 40 lbs.
Greg

Wrong. The tension on both sides will be equal (20 lbs) and the top
hook will feel 40lbs. There is nothing being added to the 40 lbs to
increase it to 80. I think you have confused the effect of a pulley
which, when rigged right, will cut the lifting force by 1/2.

It appears that *you* are the confused one here. A *movable* pulley will
cut
the lifting force in half. A *fixed* pulley only changes the direction in
which the force is applied -- and this situation is entirely analogous to
a
fixed pulley.

--------40----top-------------
/\
/ \
20/ \20
/ \
load/40 \anchor
------------bottom-------

Nope. You have a major problem he on the left side, a 40-lb weight is
suspended on a rope that has only 20 lbs tension. Doesn't work that way.

Suppose the anchor on the right is replaced by an un-anchored weight. What

weight is required on the right to balance the 40 lb weight on the left?
According to your diagram, the answer is 20 lbs. Now do you see your
error?

--------------------top--------------
\anchor /anchor or pulley
\ /
\20 /20
\ /
\ /
\/
40
load with pulley
--------------------bottom----------

Not the same situation.

No. My first diagram is wrong in that the 20lbs should be 40. The
second is correct. Or am I misunderstanding your second part?

Permit me to clarify. I agree that your second diagram is correct. My point
is
that it's not the same situation as the first diagram, and thus the loads
in the second diagram *must* be different from the loads in the first. You
now
state correctly that the loads in the first diagram should be indicated as
40,
not 20, and I wish to emphasize that this is loadS plural, i.e. in both
segments of the rope -- thus the load on the top anchor in the first diagram
is in fact 80 pounds, not 40 as you stated in your text.

Nope. The load is still only 40. The second 40 is only the -same- 40
extended to another anchor.

No, it's not the "same" 40 pounds. It's an *equal* force, but separate.

Suppose that, instead of being tied to a cleat, the rope on the right side is
supporting a second 40-pound weight. You do see, I hope, that if the weight on
the right is not the same as the weight on the left, one or the other of them
will fall. For the system to remain in equilibrium, it is necessary that both
of the weights be the same -- that the downward forces on the ropes be equal.
Agree so far? ( I hope so. )

OK, so now we have a hook with a rope looped over it, and there's a 40-lb
weight at *each* end of the rope. How much weight is the hook supporting?
If you answered "40 lbs", go back and re-read this as often as necessary until
you realize that's wrong. If you answered "80 lbs" then continue.

Now disconnect the 40-lb weight on the right, and tie that rope off to a
stationary object. The weight on the left doesn't move, proving that the
system *remains* in equilibrium -- thus the force on the right side of the
rope is the same as it was before.

And therefore the force on the hook is the same as it was before, too: 80 lbs.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
om...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"The Other Harry" wrote in message
...

The question was (and is), what happens to the load?

If the entire pot arrangement weighs 40 pounds, does half
of that load go to the top hook and half of it go to the
anchor hook?

--
Harry

I am assuming you have a rope attached to the pot, that runs up to a
hook
or
pulley attached to the ceiling,, then back down to an cleat.
If the pot weighs 40 lbs, the top hook in the ceiling, (or window
frame,
whatever!) with the pulley will be carrying 80 lbs. The tension,
(weight)
felt by the rope at the cleat will be 40 lbs.
Greg

Wrong. The tension on both sides will be equal (20 lbs) and the top
hook will feel 40lbs. There is nothing being added to the 40 lbs to
increase it to 80. I think you have confused the effect of a pulley
which, when rigged right, will cut the lifting force by 1/2.

It appears that *you* are the confused one here. A *movable* pulley
will
cut
the lifting force in half. A *fixed* pulley only changes the direction
in
which the force is applied -- and this situation is entirely analogous
to
a
fixed pulley.

--------40----top-------------
/\
/ \
20/ \20
/ \
load/40 \anchor
------------bottom-------

Nope. You have a major problem he on the left side, a 40-lb weight
is
suspended on a rope that has only 20 lbs tension. Doesn't work that
way.

Suppose the anchor on the right is replaced by an un-anchored weight.
What

weight is required on the right to balance the 40 lb weight on the
left?
According to your diagram, the answer is 20 lbs. Now do you see your
error?

--------------------top--------------
\anchor /anchor or pulley
\ /
\20 /20
\ /
\ /
\/
40
load with pulley
--------------------bottom----------

Not the same situation.

No. My first diagram is wrong in that the 20lbs should be 40. The
second is correct. Or am I misunderstanding your second part?

Permit me to clarify. I agree that your second diagram is correct. My
point
is
that it's not the same situation as the first diagram, and thus the loads
in the second diagram *must* be different from the loads in the first. You
now
state correctly that the loads in the first diagram should be indicated as
40,
not 20, and I wish to emphasize that this is loadS plural, i.e. in both
segments of the rope -- thus the load on the top anchor in the first
diagram
is in fact 80 pounds, not 40 as you stated in your text.

No, it is 40. The second 40 is sort of a ghost 40lbs as it is the
-same- 40 lbs only extended to a second anchor.

Wrong.

Try it, lift 40 lbs
directly and then run the rope over a plley and pull on it, you will
still only see 40 lbs. See me exlanation to Greg O.

I *did* try it, as I described in an earlier post. Go back to the original
post in this thread. The question is how much load is placed on the beam or
whatever that the pulley hangs from. With a weight hanging free on one side,
and the rope it hangs from tied off to a stationary object on the other side,

the load placed on the pulley's support is approximately double that of the
weight, depending on the angle of the anchored segment of the rope. The
mathematics behind this has been clearly (and correctly) described by others
in this thread, and I won't repeat it here. You can look it up if you want to

understand why this doesn't work the way you think it does.

Your explanation to Greg is just as flawed as your explanation here.

Harry K

Well what can I say. If you saw -anyone- post an explanation of their
being 80 lbs at the anchor, point the way. Everyone that has tried
(you and Greg) have been proved wrong by me, by Tom and by every
physics book in existance.

It's there, Harry, just read the thread. Try the first couple of posts that
Michael Daly made. You haven't proven anything except your own inability to
take measurements, and Tom hasn't even attempted a proof of anything, all he's
done is to say "Harry's right" without even offering any reasoning to back it
up. And you're both wrong.

In article , (Harry K) wrote:
(Tom Miller) wrote in message
...
On 14 Mar 2004 10:33:26 -0800, (Harry K)
wrote:

| (Doug Miller) wrote in message
. com...
| In article ,
(Harry K) wrote:
| (Doug Miller) wrote in message
| gy.com...
| In article ,
(Harry K) wrote:
| "Greg O" wrote in message
| ...
| "The Other Harry" wrote in message
| ...
|


snippage as everyone has seen that many times

is in fact 80 pounds, not 40 as you stated in your text.
|
| No, it is 40. The second 40 is sort of a ghost 40lbs as it is the
| -same- 40 lbs only extended to a second anchor. Try it, lift 40 lbs
| directly and then run the rope over a plley and pull on it, you will
| still only see 40 lbs. See me exlanation to Greg O.
|
| Harry K

The way to understand it better is to know that it is not a "ghost"
forty pounds, or an additional forty pounds, but rather the SAME forty
pounds.

As I have stated several times but they just ain't getting it. All
they would have to to is a simple experiment with a single cheap
scale.

Harryy, I *did* do the experiment. And it proved that you're wrong. Read my
posts. Read Greg's posts. Read Michael's posts. *You* are the one who "just
ain't getting it".

In article , (Harry K) wrote:
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor. Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

I'm not sure what you're driving it, because your description is far from
clear. One thing is sure, though: the situation you describe here is not the
same as what we've been discussing. The difference is that in the situation
we've been discussing, the rope is not attached to the upper anchor. In the
situation you describe here, it is (it's gripped in the hand).

That _makes_a_difference_. If you don't see why it does, then you need to go
back to your high school physics book until you do.

http://www.howstuffworks.com/pulley.htm

This web page speaks to the issue of how much pull is needed on the rope to
make the weight go up. But it does not adress the felt weight on the pulley
hook.

I don't have a fish spring scale to try this theory. But at the moment, my
intuition tells me that if a man on the ground is supporting a 40# weight
(through a single pulley) that the pulley hook feels 40#. The force the man
applies is directed through the pulley to the weight. Now, if the pulley has
major friction, and the pulley is jammed instead of rotating, then the force
can be applied to the ceiling hook.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.

Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

Tomorrow night we will discuss complex block and tackles, test at 10 PM!!
;-)
Greg

I'd think both of those drawings were the same -- if the pulley was rigid,
and the ropes were pulling directly on the ceiling or floor hook.

But with a pulley (smoothly) transferring the force, somehow it just doesn't
feel right. Seems like the bottom drawing oughta be

40
0 -- pulley
/ \
/ \
40 40

--or this---
80
J --Both ropes independently tied to hook
/ \
/ \
40 40

That eighty pound hook still doesn't feel right unless the pulley jams.



--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...
Harry,
Is this drawing, really any differant from

20 20
\ /
\ /
\ /
\ /
\ /
40

this one?


40
/ \
/ \
/ \
/ \
/ \
/ \
20 20

Greg

In article , (Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor. Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

Harry K

You lost me here!!!
I don't unsderstand what slack you are refering to.
Your drawing is correct though, but what we have been discussing is
differant.
Greg
Greg

You did understand the first part?
If it is the second part, the slack I am referring to is whatever is
hanging loose leading from the hand holding the line/bucket to your
foot. In effect your line/bucket hand is the anchor at the top, your
foot is the anchor at the bottom.

What we are discussing is the -same- thing.

NO! It is *not* the same thing, because you're *holding* that rope in your
hand. That apparently "minor" difference changes *everything*.

I am just trying to
simplify it down to one step at a time until you can see the logic
here.

Admirable goal. But you must be careful not to alter the problem as you
simplify, and you have just altered it.

No matter how you try to sidestep and adamantly refuse to
accept reality, there is no 80 lbs in the the original problem.

No matter how *you* try to "sidestep and adamantly refuse to accept reality",
equilibrium is equilibrium, and you're still wrong.

For some reason you seem to refuse to do any experiment that will show
you are wrong.

Harry, I'm beginning to think that your mind might be just a bit closed. I've
*done* the experiment. And I thought, going in to it, the _same_ thing you
did. (Read my original post in this thread.) The experiment proved me (and
you) wrong.

It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself.

I already have a scale. I did the experiment. You're wrong.

You have refused to believe my
readings but have not shown which if any you think are incorrect much
less -why- you think so. The closest you came was "readings all over
the place". How about some specifics?

Read your own damn post, Harry. Your numbers were inconsistent.

In article , (Harry K) wrote:
"Stormin Mormon" wrote in message
...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.

Harry, why don't *you* do the experiment again, and be more careful this time.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.

Sorry, Harry, but that's not correct. It's been explained many times already.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

Reread your high school physics text a few more times, until you understand
that it is the _same_.

In article , (Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...

Well I have attempted to explain it as simply as I can. I repeat that
the one drawing is incorrect. do your own experiment, ask a physics
teacher or as Tom says, look it up.

Harry K

I have, and have come up with answers that oppose yours!
I helped a friend build a two post automotive lift using heavy chains and
hydraulic cylinders. It will lift 10,000+ lbs. We used princibles that we
have been discussing .
Greg

Sure you came up with opposing answers! You didn't measure the forces.
My question here is where were the pulleys etc as any two hydraulic
cylinders would easily build a 10,000 lb hoist without all the monkey
motion.
If you want any credibility at all, you will do the same expiriment I
did and
-honestly- report the readings. It will cost you less than $10 if you
have to buy the scale and pulley. Thus far all you have put forth in
all you posts is 'you are wrong' 'the force is 80' etc. with no proof
at all except your rockbound belief that the force has to be 80. A
simple scale and a test will prove you wrong.

Actually, Harry, the test proves him right, and you wrong. I *did* the test,
and posted my findings. I actually did it twice, not believing what I saw the
first time. And my numbers, unlike yours, were consistent.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
wrote:
On 14 Mar 2004 10:24:11 -0800, (Harry K)
wrote:

| (Harry K) wrote in message
. com...
| "Greg O" wrote in message
...
| Harry,
| Is this drawing, really any differant from
|
| 20 20
| \ /
| \ /
| \ /
| \ /
| \ /
| 40
|
| this one?
|
|
| 40
| / \
| / \
| / \
| / \
| / \
| / \
| 20 20
|
| Greg
|
| No they are not the same: If the load in No.1 is 40 the drawing is
| correct. If the load in No.2 is 20 the drawing is incorrect. In
no.2
| with load 20 the pull on the top will be 20 not 40.
| See my experiment that I used to confirm the theory. It confirms
what
| I just said.
|
| Harry K
|
|
| A better explanation.
|
| Diagram 2 is a class 1 pulley. It only changes the direction of pull
| and does nothing to change the strain. If you were to tie off the
| left line at the top (hook) what will the strain on the hook be?
| Answer: 20 lbs, not 40. The 20lbs you are showing on the right leg is
| only the same 20 lbs extended to a different anchor, not an additonal
| 20 lbs.
|
| Diagram 1 is a class 2 pulley. It halves the load between two lines
| but requires, say, 10ft of rope pull to lift the load 5 ft.
|
| Harry K

Harry, you are absolutely and irrefutably correct. It's the difference
between two types of pulleys, one a simple pulley (the one fastened to
the ceiling) and one a moveable pulley (fastened to the weight, with
the rope tied to the ceiling on one side). It makes all the
difference.

*IF* we were discussing moveable pulleys, yes -- but we're not, and that
appears to be the source of confusion for both of you. Go back to the
original
post in this thread, and find out what the discussion is all about. Then read

some of the followups, particularly those from Michael Daly, to find out
exactly why Harry is absolutely and irrefutably INcorrect.

By the way, these are principles known for thousands of years. The
pyramids were built using these simple machines and others. Leonardo
da Vinci commented on these pulleys. It's not opinion. There's nothing
to argue about. You don't even have to prove it with geometry -- as
Yogi Bera once said, "you could look it up."

Yes, you could. You could start by looking up the initial post in this
thread.

Or you could do the simple test that has been proposed many times.

Do you EVER read anything before you post, Harry?

Go to Google, and look up my *first* post in this thread. I DID THE TEST. I
was the first one to post in this thread that I had done so. *Before* doing
the test, I had the _same_ preconceived notion that you are having such a hard
time letting go of. And the test proved that preconceived notion to be WRONG.

In article , (Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
m...

Ok. mentally tie the rope to the top anchor. What is the pull? Answer
20 lbs. Do you agree with that?

Now extend the rope to the bottom and tie it. What has changed?
Nothing.

Of course if you are adamant that 20 lbs just magically appear you
could go down to the school and ask the physics teacher. He will
probably show you the identical experiment with identical (altho more
acccurate) results I did.

Waiting your comment.

Harry K


Sure you are right if you are talking about this,

20
|
|
20
But we have been talking about this,

40
/\
/ \
/ \
20 20

Two totally differant deals!
With a load supportted by a rope that goes through a pulley shown imediately
above, there needs to be a equal force on the opisite end of the rope to
balance the load. The addition of the load used to balance the weight adds a
the additional load at the pulley.
Greg

Only problem is your diagram is wrong. Do the simple test and prove
it or just ask a teacher.

There's nothing the matter with his diagram.

YOU do the test. And pay attention to how you do it this time.

In article , "Stormin Mormon" wrote:
I'd think both of those drawings were the same -- if the pulley was rigid,
and the ropes were pulling directly on the ceiling or floor hook.

But with a pulley (smoothly) transferring the force, somehow it just doesn't
feel right. Seems like the bottom drawing oughta be

40
0 -- pulley
/ \
/ \
40 40

Nope. Top number should be 80. What on earth makes you think it should be 40?
You show a single pulley supporting *two* 40-lb weights. How could the load at
the pulley possibly be anything except 80? (plus the weight of the rope)

--or this---
80
J --Both ropes independently tied to hook
/ \
/ \
40 40

That eighty pound hook still doesn't feel right unless the pulley jams.

May not "feel right" but that's the way it is.

In article ,
Harry K wrote:
"Stormin Mormon" wrote in message ...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

Tomorrow night we will discuss complex block and tackles, test at 10 PM!!
;-)
Greg

Teh best you can hope for is an F

Harry K

Harry,

Here is a little test that you can do that will show you what is going on
and if your scale is inaccurate, the magnitude of the test will still show
you what is going on.

1. Get a 100 lb weight and tie a rope to it.
2. Pass this rope through a pulley.
3. Climb a step ladder holding said pulley.
4. Have a friend pull on the rope to lift the weight.

I'm fairly certain that you a a strong fellow and should have no problems
what-so-ever supporting a measly 100lb load while on the ladder. But I suspect
that you might have a bit of difficultly with a 200lb load.

BTW, I performed the experiment in high school science lab. The load on the
top pulley is twice the load being lifted.

Harry K wrote:
Don't bother, he won't believe you but just to prove it -again- I just
re-ran the experiment. Bucket weighed 26 lbs this time


scale reads 26 (taa daa!)
I\
I \
I \
I \
I \
I \
I \
bucket anchor
26 lb

Again he won't believe it and refuses to do the same experiment

You are either lying, or you've tied off the rope to the scale and the
anchor isn't doing anything, or possibly you don't have the scale in the
right place.

The scale will read 52 lbs assuming it's between the hook and the rope,
and the rope is free to slide such that it needs to be tied off.

-------------------------------------------------------------------------

Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

And the flaw with this reasoning is that it would fit the origial IF
and only IF you hung an additional 40 lbs on the other leg of the
rope.

If there is no force in the rope, then you've tied it off to the scale and
it certanly will read only 40 lbs, but then you've got no need for the
other leg of the rope. But if there's 40 lbs of tension in the rope, then
the rope doesn't know what that tensions coming from, whether it's a 40lb
weight or a 40 lb pull from the other end.


John
--
Remove the dead poet to e-mail, tho CC'd posts are unwelcome.
Ask me about joining the NRA.

According to :
Harry K wrote:
Don't bother, he won't believe you but just to prove it -again- I just
re-ran the experiment. Bucket weighed 26 lbs this time


scale reads 26 (taa daa!)
I\
I \
I \
I \
I \
I \
I \
bucket anchor
26 lb

Again he won't believe it and refuses to do the same experiment

You are either lying, or you've tied off the rope to the scale and the
anchor isn't doing anything, or possibly you don't have the scale in the
right place.

Or he anchored it to the bucket...

The scale will read 52 lbs assuming it's between the hook and the rope,
and the rope is free to slide such that it needs to be tied off.

Right.

Another way to think of this is that the force vectors must equal for the
thing to be in equilibrium.

Ie: the bucket is pulling down 26 pounds.
the anchor is also pulling 26 pounds (to hold the bucket _up_), but the
force vector is down.
Which is a total of 52 pounds down.
Thus, the scale must be pulling _up_ 52 pounds.

This is why shoelaces work ;-) [think about it.]
And block-and-tackle with multiple pulley sheaves.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

In article , wrote:
Harry K wrote:
Don't bother, he won't believe you but just to prove it -again- I just
re-ran the experiment. Bucket weighed 26 lbs this time


scale reads 26 (taa daa!)
I\
I \
I \
I \
I \
I \
I \
bucket anchor
26 lb

Again he won't believe it and refuses to do the same experiment

You are either lying, or you've tied off the rope to the scale and the
anchor isn't doing anything, or possibly you don't have the scale in the
right place.

I think he tied it off. A couple of his previous posts suggest that he does
not realize that whether the rope is fixed in place, or free to move, makes
all the difference in the world.

[On 15 Mar 2004 22:35:47 GMT,
(Chris Lewis) wrote:]

Or he anchored it to the bucket...

That would be right.

I have essentially given up on using my pedestrian logic
to try to understand this subject. It still seems strange
to me that it would make any difference whether the rope
is anchored directly to the hook, back down to the bucket,
or down to a separate cleat.

My opinion (which is evidently wrong) is still that there
was 40 pounds of original load. The more places that load
is distributed, the less of that load should fall on each
place. Wrong.

The best example I have seen about why I am wrong came
from the person who compared using the cleat to
counter-balancing the pot with another pot. That would
take another 40 pounds, which makes perfect sense. Hence
the combined load on the hook would increase to 80.

Using a cleat would necessarily have the same effect on
the hook.

I still cannot conceptualize where the additional weight
comes from if there is no other load/weight.

I can say these things:

- Wheat beer (with lemon) is better than ale.
- Single malt scotch is better than blends.
- Cuban cigars are better than American cigars.

Now, if I can just figure out how to buy a live-able shack
down in the Highlands of Costa Rica -- which I think I can
do -- everything will be just fine.

The only remaining problems will be how to keep out the
bugs and how to make the toilet work. Give up on those,
go get some Carne Asada and/or Pesca tacos, and it all
works.

--
Harry

"Harry K" wrote in message
om...

For some reason you seem to refuse to do any experiment that will show
you are wrong. It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself. You have refused to believe my
readings but have not shown which if any you think are incorrect much
less -why- you think so. The closest you came was "readings all over
the place". How about some specifics?

Harry K

But Harry, I have done the experiment, and it proved you wrong!
Greg

"Harry K" wrote in message
m...

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.



How many times do I need to tell you that I have done it, and it proves you
wrong!
Funny how at least two other people side with me, and you sit alone on this,
unless you include Stormy, but then his logic has been proven wrong MANY
times befrore!
Greg

"Harry K" wrote in message
om...

Sure you came up with opposing answers! You didn't measure the forces.
My question here is where were the pulleys etc as any two hydraulic
cylinders would easily build a 10,000 lb hoist without all the monkey
motion.
If you want any credibility at all, you will do the same expiriment I
did and
-honestly- report the readings. It will cost you less than $10 if you
have to buy the scale and pulley. Thus far all you have put forth in
all you posts is 'you are wrong' 'the force is 80' etc. with no proof
at all except your rockbound belief that the force has to be 80. A
simple scale and a test will prove you wrong.

Harry K


If I was wrong the hoist would not have raised his shop truck filled with
tools. We ran the truck over his scale at his wrecking yard and it weighed
~10,000 lbs. We added weight untill the lift would not raise the truck, IIRC
it was some where around 10,500lbs when the relief valve popped. If I was
wrong it would not have worked. We worked the whole thing out on paper
before it was built and he wanted a max of 10,000 lbs. for safety. After the
lift was proven to lift 10,000 lbs + we backed the relief valvee down so it
maxed out around 8,000 lbs to give a safety factor.

Funny how three people have done the "experiment" and get the same results,
differant from yours. Either you fudged the experiment, or do not understand
what we are disscussing, or you are wrong and refuse to admit it!
Greg

Greg

(John Cochran) wrote in message ...
In article ,
Harry K wrote:
"Stormin Mormon" wrote in message ...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

Tomorrow night we will discuss complex block and tackles, test at 10 PM!!
;-)
Greg

Teh best you can hope for is an F

Harry K

Harry,

Here is a little test that you can do that will show you what is going on
and if your scale is inaccurate, the magnitude of the test will still show
you what is going on.

1. Get a 100 lb weight and tie a rope to it.
2. Pass this rope through a pulley.
3. Climb a step ladder holding said pulley.
4. Have a friend pull on the rope to lift the weight.

I'm fairly certain that you a a strong fellow and should have no problems
what-so-ever supporting a measly 100lb load while on the ladder. But I suspect
that you might have a bit of difficultly with a 200lb load.

BTW, I performed the experiment in high school science lab. The load on the
top pulley is twice the load being lifted.

Sorry but it isn't as my simple test that anyone can do in a minute
proves otherwise. If you did it in HS lab and got 2x the load you
failed the experiment. Someone way up thread posted at link to a site
giving the good explanation.

Harry K

(Doug Miller) wrote in message . com...
In article , (Harry K) wrote:
"Stormin Mormon" wrote in message
...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.

Harry, why don't *you* do the experiment again, and be more careful this time.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.

Sorry, Harry, but that's not correct. It's been explained many times already.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

Reread your high school physics text a few more times, until you understand
that it is the _same_.

I do not understand you and Greg and now Steve. The test is a simple
one, anyone can do it and it will prove all three of you are wrong.
Why do you not do it. Yes, yes I know. 'I know what I know and don't
confuse me with facts'

Ignorance - not knowing something
Stupidity - refusing to learn when led to the source.

Do the test then get back to the thread. Also see below where I did
repeat the test using only one scale this time thus eliminating one
variation.

Harry K

(Doug Miller) wrote in message om...
In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"The Other Harry" wrote in message
...

The question was (and is), what happens to the load?

If the entire pot arrangement weighs 40 pounds, does half
of that load go to the top hook and half of it go to the
anchor hook?

--
Harry

I am assuming you have a rope attached to the pot, that runs up to a
hook
or
pulley attached to the ceiling,, then back down to an cleat.
If the pot weighs 40 lbs, the top hook in the ceiling, (or window
frame,
whatever!) with the pulley will be carrying 80 lbs. The tension,
(weight)
felt by the rope at the cleat will be 40 lbs.
Greg

Wrong. The tension on both sides will be equal (20 lbs) and the top
hook will feel 40lbs. There is nothing being added to the 40 lbs to
increase it to 80. I think you have confused the effect of a pulley
which, when rigged right, will cut the lifting force by 1/2.

It appears that *you* are the confused one here. A *movable* pulley will
cut
the lifting force in half. A *fixed* pulley only changes the direction in
which the force is applied -- and this situation is entirely analogous to
a
fixed pulley.

--------40----top-------------
/\
/ \
20/ \20
/ \
load/40 \anchor
------------bottom-------

Nope. You have a major problem he on the left side, a 40-lb weight is
suspended on a rope that has only 20 lbs tension. Doesn't work that way.

Suppose the anchor on the right is replaced by an un-anchored weight. What

weight is required on the right to balance the 40 lb weight on the left?
According to your diagram, the answer is 20 lbs. Now do you see your
error?

--------------------top--------------
\anchor /anchor or pulley
\ /
\20 /20
\ /
\ /
\/
40
load with pulley
--------------------bottom----------

Not the same situation.

No. My first diagram is wrong in that the 20lbs should be 40. The
second is correct. Or am I misunderstanding your second part?

Permit me to clarify. I agree that your second diagram is correct. My point
is
that it's not the same situation as the first diagram, and thus the loads
in the second diagram *must* be different from the loads in the first. You
now
state correctly that the loads in the first diagram should be indicated as
40,
not 20, and I wish to emphasize that this is loadS plural, i.e. in both
segments of the rope -- thus the load on the top anchor in the first diagram
is in fact 80 pounds, not 40 as you stated in your text.

Nope. The load is still only 40. The second 40 is only the -same- 40
extended to another anchor.

No, it's not the "same" 40 pounds. It's an *equal* force, but separate.

Suppose that, instead of being tied to a cleat, the rope on the right side is
supporting a second 40-pound weight. You do see, I hope, that if the weight on
the right is not the same as the weight on the left, one or the other of them
will fall. For the system to remain in equilibrium, it is necessary that both
of the weights be the same -- that the downward forces on the ropes be equal.
Agree so far? ( I hope so. )

OK, so now we have a hook with a rope looped over it, and there's a 40-lb
weight at *each* end of the rope. How much weight is the hook supporting?
If you answered "40 lbs", go back and re-read this as often as necessary until
you realize that's wrong. If you answered "80 lbs" then continue.

Now disconnect the 40-lb weight on the right, and tie that rope off to a
stationary object. The weight on the left doesn't move, proving that the
system *remains* in equilibrium -- thus the force on the right side of the
rope is the same as it was before.

And therefore the force on the hook is the same as it was before, too: 80 lbs.


Yep, the weight with -two- 40lbs is 80 lbs on the hooks. Your mistake
is that there is only -one- 40 lb weight. Question. If you tie off
to the hook how much force is on the hook? To insist that there is 80
lbs when it is tied to the bottom cleat in the face of proof easily
availabe in books, on the net, even my explanations can be understood.
Refusal to due a simple 1 minute test to see if your adamant stance
is correct I -do not- understand. The only thing I can figure is you
are afraid of proving yourself wrong.

Harry K

Is isn't the things you know that will get you, it is what you know
that is wrong that will bite you in the ass.

Well, now that you've figured out from my one mistake that I "don't know
what I'm talking about", I've figured out from your reply that you are
impolite in every situation, and can't continue a normal conversation.

I did talk with a couple other people, and the consensus seems to be that
the ceilin ghook would be feeling 80 pounds. It was an interesting mental
adventure, I may someday scale it out just for fun.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.

Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

Tomorrow night we will discuss complex block and tackles, test at 10 PM!!
;-)
Greg

(Doug Miller) wrote in message . com...
In article , (Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor. Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

Harry K

You lost me here!!!
I don't unsderstand what slack you are refering to.
Your drawing is correct though, but what we have been discussing is
differant.
Greg
Greg

You did understand the first part?
If it is the second part, the slack I am referring to is whatever is
hanging loose leading from the hand holding the line/bucket to your
foot. In effect your line/bucket hand is the anchor at the top, your
foot is the anchor at the bottom.

What we are discussing is the -same- thing.

NO! It is *not* the same thing, because you're *holding* that rope in your
hand. That apparently "minor" difference changes *everything*.


----------------------------------------------------------------------------
Oh for gods sake. How dense are you? Here to make it -really- simple
for you which I shouldn't have had to explain. Your had is
substituting for the top anchor! Try again but make some sense.
-----------------------------------------------------------------------------


I am just trying to
simplify it down to one step at a time until you can see the logic
here.

Admirable goal. But you must be careful not to alter the problem as you
simplify, and you have just altered it.
-------------------------------------------------------

Okay, show me where it has been altered. You can't do it, it is the
same problem with your hand substituting for the hook.
----------------------------------------------------

No matter how you try to sidestep and adamantly refuse to
accept reality, there is no 80 lbs in the the original problem.

No matter how *you* try to "sidestep and adamantly refuse to accept reality",
equilibrium is equilibrium, and you're still wrong.

For some reason you seem to refuse to do any experiment that will show
you are wrong.

Harry, I'm beginning to think that your mind might be just a bit closed. I've
*done* the experiment. And I thought, going in to it, the _same_ thing you
did. (Read my original post in this thread.) The experiment proved me (and
you) wrong.

================================================== ========================
I just checked all the posts I could find and I didn't find one where
you did any experiment. If you did please give me the number of the
post and I will rechcheck it.

I did see where you caught me on the 20 vs 40 lb on left right side
which I admitted to screwing up.

-----------------------------------------------------------------
It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself.

I already have a scale. I did the experiment. You're wrong.


-----------------------------------------------------------
So do it again only give the diagram you use and the readings you get.
It will only take minute and involve only two weighings (1 for bucket
then one for strain on hook). I don't see what is keeping you from
doing it, it isn't like it'll cost you anything. It only took me a
minute to repeat the experiment this morning. Buket 26 lbs, hook 26
lbs with the bitter end of line tied off to a bottom anchor. Go ahead
and do it, don't just run your mouth until you do.
-------------------------------------------------------------


You have refused to believe my
readings but have not shown which if any you think are incorrect much
less -why- you think so. The closest you came was "readings all over
the place". How about some specifics?

Read your own damn post, Harry. Your numbers were inconsistent.

Again, Post just -one- of my readings that is inconsistent and we will
discuss it. All you have done is claim numerous times that I was
careless, that the readings are wrong, that the instruments are bad,
etc. It will only take a simple cut and paste for you to really
discuss where you have problems with the readings.

Harry K

In article ,
Harry K wrote:
(John Cochran) wrote in message ...
In article ,
Harry K wrote:
"Stormin Mormon" wrote in message ...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

One 40 lb kid is the flower pot, the other 40 lb kid is the force on other
end of the rope needed to suspend the pot, and the fulcrum is the pulley or
hook.

Tomorrow night we will discuss complex block and tackles, test at 10 PM!!
;-)
Greg

Teh best you can hope for is an F

Harry K

Harry,

Here is a little test that you can do that will show you what is going on
and if your scale is inaccurate, the magnitude of the test will still show
you what is going on.

1. Get a 100 lb weight and tie a rope to it.
2. Pass this rope through a pulley.
3. Climb a step ladder holding said pulley.
4. Have a friend pull on the rope to lift the weight.

I'm fairly certain that you a a strong fellow and should have no problems
what-so-ever supporting a measly 100lb load while on the ladder. But I suspect
that you might have a bit of difficultly with a 200lb load.

BTW, I performed the experiment in high school science lab. The load on the
top pulley is twice the load being lifted.

Sorry but it isn't as my simple test that anyone can do in a minute
proves otherwise. If you did it in HS lab and got 2x the load you
failed the experiment. Someone way up thread posted at link to a site
giving the good explanation.

Harry K

Harry,
I'll see if I can explain things to you one more and then I'll ignore this
thread because you're untrainable.

I think that you'll agree that force times distance is a constant whenever
you are using pulleys, levers or any other form of mechanical advantage.
For example, if you have a 2 to 1 mechanical advantage, then if you apply
a force of 1lb over a distance of 2 feet, then you will move a load of
2 lbs a distance of 1 foot. Conversely, if you have a 1 to 2 mechanical
disadvantage, then applying a force of 2 lbs over a distance of 1 foot
will result in having only 1 lb of force, but over a distance of 2 feet.

eg. A lever

Apply 1 lb here Get 2 lbs of force over half the distance here.
| ^
| |
| |
V |
------------------------------------------
^

eg. A pulley

Apply 1 lbs of force here
^
|
anchor . |
| |
| |
| |
| |
| |
| |
| |
| |
| |
O
+----------------+------------------+
| Lift 2 lbs here half the distance |
+-----------------------------------+

Now for the situition that we have here


|
|
O\
| \
| \
| \ --- 10 feet of rope with 5 feet on both sides of
| \ pulley. The weight is 5 feet below the pulley.
| \
| \
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+

Imagine with the above diagram that you can grab the top pulley and lift it
1 foot higher.

How much higher will the 40lb weight go?
Well according to me, that 40lb weight will go 2 feet higher.

|
|
O\
| \
| \
| \ --- Still have 10 feet of rope, but since the
| \ pulley moved, 6 feet of the rope is on the
| \ anchor side, leaving only 4 feet on the load
| \ side.
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+
The 40 lb load only has 4 feet of distance from the pulley, therefore it's
1 foot closer to the pulley. But since the pulley is now 1 foot higher, the
load is now 2 feet higher than it was when it started. The load was lifted
2 feet.

But, you only raised the pulley 1 foot. Since force times distance must
match, then how much force did you need to apply to the pulley in order
to lift it?

I get

40 lbs times 2 feet = ? pounds times 1 foot
80 foot lbs = 80 pounds times 1 foot
80 foot lbs = 80 foot lbs.

Now it doesn't matter how far you move the pulley. But in order to lift
that pulley, you have to apply 80 lbs of force against it because that is
the amount of load that it is carrying.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
"Stormin Mormon" wrote in message
...
Y'know, that sure sounds reasonable. I don't have a fisherman's spring
scale, but your answer sure sounds reasonable.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Greg O" wrote in message
...

"Stormin Mormon" wrote in message
...
Hey, mike, you're confusing the issue! If you have 500 pounds hanging on
a
block and tackle, it doesn't matter how many ropes, the screwhook at top
is
still holding 500 pounds (and now I'm confusing the issue).

--


Stormy, you have proven again, without a doubt that you do not know what
you
are talking about!
In a situation I described, the hook in the ceiling will feel 2 times the
weight of the flower pot. If you use a more complex block and tackle, one
with several pulleys top and bottem, the more wraps and pulleys you use
the
lower the load on the hook in the ceiling, but it will never be less than
the weight of the flower pot, plus the weight of the block and tackle and
the force needed on the rope to suspend the object.

The only way to have less load on the hook than the object weighs is to
use
a pulley and the flower pot, and two hooks on the ceiling. then each hook
will hold 1/2 the weight.

If anyone fails to understand this, do as another poster did and get a
fish
scale, a pulley, a weight, and a pice of rope, and try it your self!

Well stormin, don't bother to try it as Greg won't believe the
readings anyhow.
And take note that Greg refuses to do the experiment.

Harry, why don't *you* do the experiment again, and be more careful this
time.


Think of ot this way, the pot weighs 40 lbs. If you had a pot hanging on a
length of rope hooked to the ceiling, the rope, hook and all feel a load
of
40 lbs. If you add pulley at the ceiling and run the rope over it and back
down, you need to apply a force of 40 lbs to suspend the pot, any more or
less force applied and the pot will go up or down. Now you have TWO 40 lb
loads, the pot, and the force to ballance the weight of the pot, which
will
be equal. In this case 40 lbs X 2 = 80 lbs.


You just failed the test again. You don't have two 40 lb loads, you
have one extended over two anchors.

Sorry, Harry, but that's not correct. It's been explained many times already.


Another way is to think of this whole rope and flower pot situation as a
tetter-totter. You have a 40 lb kid on one side, so you need a 40 lb kid
on
the other side to balance it. The weight the fulcrum of the tetter-totter
feels is 80 lbs. Asssuming the tetter-totter weighs nothing.


This part you have right but it has nothing to do with the pulley
problem.

Reread your high school physics text a few more times, until you understand
that it is the _same_.

I do not understand you and Greg and now Steve. The test is a simple
one, anyone can do it and it will prove all three of you are wrong.
Why do you not do it. Yes, yes I know. 'I know what I know and don't
confuse me with facts'

I have done the test, Harry. It proves you wrong. Read my first post in this
thread: I began with the same preconceived notion that you did. The
difference is that when experimental results contradicted that preconceived
notion, I abandoned it, whereas you insist on clinging to it.

Ignorance - not knowing something

You began here...

Stupidity - refusing to learn when led to the source.

... and are now here.

Do the test then get back to the thread. Also see below where I did
repeat the test using only one scale this time thus eliminating one
variation.

Harry, I really have to wonder if you have actually read ANY of the posts that
you have responded to.

I HAVE ALREADY DONE THE TEST. IT PROVES YOU WRONG.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
om...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"The Other Harry" wrote in message
...

The question was (and is), what happens to the load?

If the entire pot arrangement weighs 40 pounds, does half
of that load go to the top hook and half of it go to the
anchor hook?

--
Harry

I am assuming you have a rope attached to the pot, that runs up to a
hook
or
pulley attached to the ceiling,, then back down to an cleat.
If the pot weighs 40 lbs, the top hook in the ceiling, (or window
frame,
whatever!) with the pulley will be carrying 80 lbs. The tension,
(weight)
felt by the rope at the cleat will be 40 lbs.
Greg

Wrong. The tension on both sides will be equal (20 lbs) and the top
hook will feel 40lbs. There is nothing being added to the 40 lbs to
increase it to 80. I think you have confused the effect of a pulley
which, when rigged right, will cut the lifting force by 1/2.

It appears that *you* are the confused one here. A *movable* pulley
will
cut
the lifting force in half. A *fixed* pulley only changes the direction
in
which the force is applied -- and this situation is entirely analogous
to
a
fixed pulley.

--------40----top-------------
/\
/ \
20/ \20
/ \
load/40 \anchor
------------bottom-------

Nope. You have a major problem he on the left side, a 40-lb weight
is
suspended on a rope that has only 20 lbs tension. Doesn't work that
way.

Suppose the anchor on the right is replaced by an un-anchored weight.
What

weight is required on the right to balance the 40 lb weight on the
left?
According to your diagram, the answer is 20 lbs. Now do you see your
error?

--------------------top--------------
\anchor /anchor or pulley
\ /
\20 /20
\ /
\ /
\/
40
load with pulley
--------------------bottom----------

Not the same situation.

No. My first diagram is wrong in that the 20lbs should be 40. The
second is correct. Or am I misunderstanding your second part?

Permit me to clarify. I agree that your second diagram is correct. My
point
is
that it's not the same situation as the first diagram, and thus the loads
in the second diagram *must* be different from the loads in the first. You
now
state correctly that the loads in the first diagram should be indicated as
40,
not 20, and I wish to emphasize that this is loadS plural, i.e. in both
segments of the rope -- thus the load on the top anchor in the first
diagram
is in fact 80 pounds, not 40 as you stated in your text.

Nope. The load is still only 40. The second 40 is only the -same- 40
extended to another anchor.

No, it's not the "same" 40 pounds. It's an *equal* force, but separate.

Suppose that, instead of being tied to a cleat, the rope on the right side is

supporting a second 40-pound weight. You do see, I hope, that if the weight
on
the right is not the same as the weight on the left, one or the other of them

will fall. For the system to remain in equilibrium, it is necessary that both

of the weights be the same -- that the downward forces on the ropes be equal.
Agree so far? ( I hope so. )

OK, so now we have a hook with a rope looped over it, and there's a 40-lb
weight at *each* end of the rope. How much weight is the hook supporting?
If you answered "40 lbs", go back and re-read this as often as necessary
until
you realize that's wrong. If you answered "80 lbs" then continue.

Now disconnect the 40-lb weight on the right, and tie that rope off to a
stationary object. The weight on the left doesn't move, proving that the
system *remains* in equilibrium -- thus the force on the right side of the
rope is the same as it was before.

And therefore the force on the hook is the same as it was before, too: 80
lbs.


Yep, the weight with -two- 40lbs is 80 lbs on the hooks. Your mistake
is that there is only -one- 40 lb weight.

I make no mistake here. *Your* mistake is failing to realize that the tied-off
rope is exerting a 40-lb force *also*.

Question. If you tie off
to the hook how much force is on the hook?

Obviously 40 lb -- but so what? That's irrelevant to the situation at hand.

To insist that there is 80
lbs when it is tied to the bottom cleat in the face of proof easily
availabe in books, on the net, even my explanations can be understood.

Cite just one book that supports your position.

Refusal to due a simple 1 minute test to see if your adamant stance
is correct I -do not- understand. The only thing I can figure is you
are afraid of proving yourself wrong.

READ MY POSTS, HARRY. I *HAVE*DONE*THE*TEST*ALREADY*. IT PROVES THAT YOU ARE
W*R*O*N*G.

Harry K

Is isn't the things you know that will get you, it is what you know
that is wrong that will bite you in the ass.

Take that to heart, Harry. You're making a fool of yourself here.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor. Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

Harry K

You lost me here!!!
I don't unsderstand what slack you are refering to.
Your drawing is correct though, but what we have been discussing is
differant.
Greg
Greg

You did understand the first part?
If it is the second part, the slack I am referring to is whatever is
hanging loose leading from the hand holding the line/bucket to your
foot. In effect your line/bucket hand is the anchor at the top, your
foot is the anchor at the bottom.

What we are discussing is the -same- thing.

NO! It is *not* the same thing, because you're *holding* that rope in your
hand. That apparently "minor" difference changes *everything*.


----------------------------------------------------------------------------
Oh for gods sake. How dense are you? Here to make it -really- simple
for you which I shouldn't have had to explain. Your had is
substituting for the top anchor! Try again but make some sense.
-----------------------------------------------------------------------------

I'm obviously less dense than you, at any rate, because I can see that whether
the rope is free to move over the top support, or fixed at the top support,
makes a difference, and you don't.

The hand is *not* substituting for the top anchor *unless* the hand does not
grip the rope, but allows it to slide through -- remember that in the
situation posed by the original poster, the segment of the rope suspending the
weight is *not* attached to any "anchor" at the top, but merely passed through
a hook.

It _makes_a_difference_.


I am just trying to
simplify it down to one step at a time until you can see the logic
here.

Admirable goal. But you must be careful not to alter the problem as you
simplify, and you have just altered it.
-------------------------------------------------------

Okay, show me where it has been altered. You can't do it, it is the
same problem with your hand substituting for the hook.
----------------------------------------------------

Speaking of dense... I *did* show you where it's been altered, but you won't
see it. In the original problem, the rope was free to move over the top
support, and in your erroneous simplification of it, it's not.

No matter how you try to sidestep and adamantly refuse to
accept reality, there is no 80 lbs in the the original problem.

No matter how *you* try to "sidestep and adamantly refuse to accept reality",

equilibrium is equilibrium, and you're still wrong.

For some reason you seem to refuse to do any experiment that will show
you are wrong.

Harry, I'm beginning to think that your mind might be just a bit closed. I've

*done* the experiment. And I thought, going in to it, the _same_ thing you
did. (Read my original post in this thread.) The experiment proved me (and
you) wrong.

================================================= =========================
I just checked all the posts I could find and I didn't find one where
you did any experiment. If you did please give me the number of the
post and I will rechcheck it.

Up until this point, I figured that you were just dense and stubborn. Now, I
have proof that you're a liar. You not only read that post, you _responded_ to
it:

http://www.google.com/groups?hl=en&l...&threadm=83Z4c.
34291%24PY.30616%40newssvr26.news.prodigy.
com&rnum=1&prev=/groups%3Fnum%3D100%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-
8%26as_drrb%3Dq%26q%3Dfiguring%2Bloads%2Bgroup%253 Aalt.home.
repair%26as_qdr%3Dw%26btnG%3DGoogle%2BSearch

I did see where you caught me on the 20 vs 40 lb on left right side
which I admitted to screwing up.

-----------------------------------------------------------------
It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself.

I already have a scale. I did the experiment. You're wrong.


-----------------------------------------------------------
So do it again only give the diagram you use and the readings you get.
It will only take minute and involve only two weighings (1 for bucket
then one for strain on hook). I don't see what is keeping you from
doing it, it isn't like it'll cost you anything. It only took me a
minute to repeat the experiment this morning. Buket 26 lbs, hook 26
lbs with the bitter end of line tied off to a bottom anchor. Go ahead
and do it, don't just run your mouth until you do.
-------------------------------------------------------------

Either you're lying, or you had the rope tied off to the scale. If it's not
free to move, it's not a replication of the original problem.

(Doug Miller) wrote in message . com...
In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor. Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

Harry K

You lost me here!!!
I don't unsderstand what slack you are refering to.
Your drawing is correct though, but what we have been discussing is
differant.
Greg
Greg

You did understand the first part?
If it is the second part, the slack I am referring to is whatever is
hanging loose leading from the hand holding the line/bucket to your
foot. In effect your line/bucket hand is the anchor at the top, your
foot is the anchor at the bottom.

What we are discussing is the -same- thing.

NO! It is *not* the same thing, because you're *holding* that rope in your
hand. That apparently "minor" difference changes *everything*.


----------------------------------------------------------------------------
Oh for gods sake. How dense are you? Here to make it -really- simple
for you which I shouldn't have had to explain. Your had is
substituting for the top anchor! Try again but make some sense.
-----------------------------------------------------------------------------

I'm obviously less dense than you, at any rate, because I can see that whether
the rope is free to move over the top support, or fixed at the top support,
makes a difference, and you don't.

The hand is *not* substituting for the top anchor *unless* the hand does not
grip the rope, but allows it to slide through -- remember that in the
situation posed by the original poster, the segment of the rope suspending the
weight is *not* attached to any "anchor" at the top, but merely passed through
a hook.

It _makes_a_difference_.


I am just trying to
simplify it down to one step at a time until you can see the logic
here.

Admirable goal. But you must be careful not to alter the problem as you
simplify, and you have just altered it.
-------------------------------------------------------

Okay, show me where it has been altered. You can't do it, it is the
same problem with your hand substituting for the hook.
----------------------------------------------------

Speaking of dense... I *did* show you where it's been altered, but you won't
see it. In the original problem, the rope was free to move over the top
support, and in your erroneous simplification of it, it's not.

No matter how you try to sidestep and adamantly refuse to
accept reality, there is no 80 lbs in the the original problem.

No matter how *you* try to "sidestep and adamantly refuse to accept reality",

equilibrium is equilibrium, and you're still wrong.

For some reason you seem to refuse to do any experiment that will show
you are wrong.

Harry, I'm beginning to think that your mind might be just a bit closed. I've

*done* the experiment. And I thought, going in to it, the _same_ thing you
did. (Read my original post in this thread.) The experiment proved me (and
you) wrong.

================================================= =========================
I just checked all the posts I could find and I didn't find one where
you did any experiment. If you did please give me the number of the
post and I will rechcheck it.

Up until this point, I figured that you were just dense and stubborn. Now, I
have proof that you're a liar. You not only read that post, you _responded_ to
it:

http://www.google.com/groups?hl=en&l...&threadm=83Z4c.
34291%24PY.30616%40newssvr26.news.prodigy.
com&rnum=1&prev=/groups%3Fnum%3D100%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-
8%26as_drrb%3Dq%26q%3Dfiguring%2Bloads%2Bgroup%253 Aalt.home.
repair%26as_qdr%3Dw%26btnG%3DGoogle%2BSearch

I did see where you caught me on the 20 vs 40 lb on left right side
which I admitted to screwing up.

-----------------------------------------------------------------
It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself.

I already have a scale. I did the experiment. You're wrong.


-----------------------------------------------------------
So do it again only give the diagram you use and the readings you get.
It will only take minute and involve only two weighings (1 for bucket
then one for strain on hook). I don't see what is keeping you from
doing it, it isn't like it'll cost you anything. It only took me a
minute to repeat the experiment this morning. Buket 26 lbs, hook 26
lbs with the bitter end of line tied off to a bottom anchor. Go ahead
and do it, don't just run your mouth until you do.
-------------------------------------------------------------

Either you're lying, or you had the rope tied off to the scale. If it's not
free to move, it's not a replication of the original problem.

I had assumed you were at least bright enough to realize the rope
would be sliding through the hand. Well after all your incorrect bs
and refusal to do a simple test I should have known better.

No you did -not- do the test or if you did you are lying about your
results. There is no reasonable explanation for either part of that.
Why lie about doing it or about the results when anyone with a spring
scale can prove you wrong in less than a minute. I just did -again-.

Do the experiment again and show your results. Here is mine which I
just repeated:

HOOK
scale 22 to 22.5
I
I
I
I
I
Bucket 21.5 lbs

The scale is so short that accurate reading to even 1/2 lb is shaky.
The 22 to 22.5 depended upon how I eased the rope going over the hook,
yes it did change somewhat but not by 20 lbs.
You will find those same readings predicted in any basic physics texts
you use as a reference.

Your turn or are you still scared?? I don't understand adamant
refusal to do a 1 minute test. If you are correct you win easily.
Just remember not to lie as anyone can check it in less than a minute.

Harry K

whole bunch of snippage

To insist that there is 80
lbs when it is tied to the bottom cleat in the face of proof easily
availabe in books, on the net, even my explanations can be understood.

Cite just one book that supports your position.


Any basic physics text. If you have a Jr high student, just check one
of his science books.

Refusal to due a simple 1 minute test to see if your adamant stance
is correct I -do not- understand. The only thing I can figure is you
are afraid of proving yourself wrong.

READ MY POSTS, HARRY. I *HAVE*DONE*THE*TEST*ALREADY*. IT PROVES THAT YOU ARE
W*R*O*N*G.

No, you did not do it, All you have done is -say- you have and your
purported results prove you didn't.

Harry K

Is isn't the things you know that will get you, it is what you know
that is wrong that will bite you in the ass.

Take that to heart, Harry. You're making a fool of yourself here.

If you do the test you are going to have a -very- red face.

Harry K

(Doug Miller) wrote in message . com...
In article , (Harry K) wrote:

bunch more snippage


This part you have right but it has nothing to do with the pulley
problem.

Reread your high school physics text a few more times, until you understand
that it is the _same_.

I do not understand you and Greg and now Steve. The test is a simple
one, anyone can do it and it will prove all three of you are wrong.
Why do you not do it. Yes, yes I know. 'I know what I know and don't
confuse me with facts'

I have done the test, Harry. It proves you wrong. Read my first post in this
thread: I began with the same preconceived notion that you did. The
difference is that when experimental results contradicted that preconceived
notion, I abandoned it, whereas you insist on clinging to it.

Ignorance - not knowing something

You began here...

Stupidity - refusing to learn when led to the source.

.. and are now here.

Do the test then get back to the thread. Also see below where I did
repeat the test using only one scale this time thus eliminating one
variation.

Harry, I really have to wonder if you have actually read ANY of the posts that
you have responded to.

I HAVE ALREADY DONE THE TEST. IT PROVES YOU WRONG.

Shouting does not increase the believability of a lie. You didn't do
it, I have, 3 times now and every result matches what physics texts
say. Where are your diagrams and readings?

I see you still refuse to address why you say my readings in the first
test are wrong. Oh I know why. Because it says that the strain on
the hook is 22 lbs when you just -know- it has to be 44. Your only
out is to claim error of instrument, reading or procedure.
Unfortunately it wasn't nor is it in the next two tests.

I haven't decided yet but I just may go to the local library and give
you a specific cite. By the way, You are the one who claimed I am
mistaken in your first or second post. By protocol it is -you- who
should be doing the research.

Harry K

(John Cochran) wrote in message ...
In article ,
Harry K wrote:


heavy snippage

Here is a little test that you can do that will show you what is going on
and if your scale is inaccurate, the magnitude of the test will still show
you what is going on.

1. Get a 100 lb weight and tie a rope to it.
2. Pass this rope through a pulley.
3. Climb a step ladder holding said pulley.
4. Have a friend pull on the rope to lift the weight.

I'm fairly certain that you a a strong fellow and should have no problems
what-so-ever supporting a measly 100lb load while on the ladder. But I suspect
that you might have a bit of difficultly with a 200lb load.

BTW, I performed the experiment in high school science lab. The load on the
top pulley is twice the load being lifted.

Sorry but it isn't as my simple test that anyone can do in a minute
proves otherwise. If you did it in HS lab and got 2x the load you
failed the experiment. Someone way up thread posted at link to a site
giving the good explanation.

Harry K

Harry,
I'll see if I can explain things to you one more and then I'll ignore this
thread because you're untrainable.

I think that you'll agree that force times distance is a constant whenever
you are using pulleys, levers or any other form of mechanical advantage.
For example, if you have a 2 to 1 mechanical advantage, then if you apply
a force of 1lb over a distance of 2 feet, then you will move a load of
2 lbs a distance of 1 foot. Conversely, if you have a 1 to 2 mechanical
disadvantage, then applying a force of 2 lbs over a distance of 1 foot
will result in having only 1 lb of force, but over a distance of 2 feet.

eg. A lever

Apply 1 lb here Get 2 lbs of force over half the distance here.
| ^
| |
| |
V |
------------------------------------------
^

eg. A pulley

Apply 1 lbs of force here
^
|
anchor . |
| |
| |
| |
| |
| |
| |
| |
| |
| |
O
+----------------+------------------+
| Lift 2 lbs here half the distance |
+-----------------------------------+

Now for the situition that we have here


|
|
O\
| \
| \
| \ --- 10 feet of rope with 5 feet on both sides of
| \ pulley. The weight is 5 feet below the pulley.
| \
| \
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+

Imagine with the above diagram that you can grab the top pulley and lift it
1 foot higher.

How much higher will the 40lb weight go?
Well according to me, that 40lb weight will go 2 feet higher.

|
|
O\
| \
| \
| \ --- Still have 10 feet of rope, but since the
| \ pulley moved, 6 feet of the rope is on the
| \ anchor side, leaving only 4 feet on the load
| \ side.
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+
The 40 lb load only has 4 feet of distance from the pulley, therefore it's
1 foot closer to the pulley. But since the pulley is now 1 foot higher, the
load is now 2 feet higher than it was when it started. The load was lifted
2 feet.

Yep, basic physics to this point.

But, you only raised the pulley 1 foot. Since force times distance must
match, then how much force did you need to apply to the pulley in order
to lift it?

I get

40 lbs times 2 feet = ? pounds times 1 foot
80 foot lbs = 80 pounds times 1 foot
80 foot lbs = 80 foot lbs.

Yep your mind experiment and results match physics.

Now it doesn't matter how far you move the pulley. But in order to lift
that pulley, you have to apply 80 lbs of force against it because that is
the amount of load that it is carrying.

See your error? You have translated the Class 1 pulley in the problem
into a Class 2 pulley in your example. Just invert your diagram and
you will see that the pulley is attached to your hand and you are in
effect pulling the 40 lb wt 1 foot to lift your hand 2 ft. Class 2
pulley.

Here is your diagram of the original problem.

Now for the situition that we have here


|
|
O\
| \
| \
| \ --- 10 feet of rope with 5 feet on both sides of
| \ pulley. The weight is 5 feet below the pulley.
| \
| \
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+


Now we both agree that the force on both legs of the rope is 40lbs
Where does the second 40 come from?

To make it clear that it is the -same- 40 lbs:

Tie the right leg to the weight. That is the same as tieing it to an
anchor.
The weight will remain quite nicely right where it is.
What is the pull on the hook?? Where did the 40 lbs go??

I hope you answer this as you do appear to know what you are talking
about. Just don't let what seems logical lead you down stray paths.
Yes, on first glance the original problem appears to need a 80 lb
strain but unfortunately it isn't true in real life. A simple test (or
reference to any physics text) will show you in less than a minute.

Harry K

wrote in message ...
Harry K wrote:
Don't bother, he won't believe you but just to prove it -again- I just
re-ran the experiment. Bucket weighed 26 lbs this time


scale reads 26 (taa daa!)
I\
I \
I \
I \
I \
I \
I \
bucket anchor
26 lb

Again he won't believe it and refuses to do the same experiment

You are either lying, or you've tied off the rope to the scale and the
anchor isn't doing anything, or possibly you don't have the scale in the
right place.

So do the test yourself, I am neither lying nor had the rope tied off
wrong. It was actually tied pretty close to the diagram, i.e.,
vertical to hook and some angle off to side (bench vice)

Are you another one that refused to do a simple 1 minute test?


The scale will read 52 lbs assuming it's between the hook and the rope,
and the rope is free to slide such that it needs to be tied off.



Try it yourself!

Harry K

(Chris Lewis) wrote in message ...
According to :
Harry K wrote:
Don't bother, he won't believe you but just to prove it -again- I just
re-ran the experiment. Bucket weighed 26 lbs this time


scale reads 26 (taa daa!)
I\
I \
I \
I \
I \
I \
I \
bucket anchor
26 lb

Again he won't believe it and refuses to do the same experiment

You are either lying, or you've tied off the rope to the scale and the
anchor isn't doing anything, or possibly you don't have the scale in the
right place.

Or he anchored it to the bucket...


Hey, good point!. In practice it doesn't matter if the rope is
attached to an anchor or tied back to the bucket. The result is the
same. No forces are changed and the bucket remains in place. Think
about it.

The scale will read 52 lbs assuming it's between the hook and the rope,
and the rope is free to slide such that it needs to be tied off.

Right.


Yep, and that is just how I rigged it, scale from hook to rope and I
eased the rope on the scale several times before reading. Try it
yourself. It will only take you a minute.

Another way to think of this is that the force vectors must equal for the
thing to be in equilibrium.

Ie: the bucket is pulling down 26 pounds.
the anchor is also pulling 26 pounds (to hold the bucket _up_), but the
force vector is down.
Which is a total of 52 pounds down.
Thus, the scale must be pulling _up_ 52 pounds.

This is why shoelaces work ;-) [think about it.]
And block-and-tackle with multiple pulley sheaves.

But now you are talking about class 2 pulley instead of the class 1 in
the problem.

Harry K

In article ,
Harry K wrote:
(John Cochran) wrote in message ...
In article ,
Harry K wrote:
SNIP....
Here is your diagram of the original problem.

Now for the situition that we have here


|
|
O\
| \
| \
| \ --- 10 feet of rope with 5 feet on both sides of
| \ pulley. The weight is 5 feet below the pulley.
| \
| \
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+


Now we both agree that the force on both legs of the rope is 40lbs
Where does the second 40 come from?

To make it clear that it is the -same- 40 lbs:

Tie the right leg to the weight. That is the same as tieing it to an
anchor.

No it isn't. If you tie the other end of the rope to the load instead
of the anchor, this is what you get.


|
|
O
| |
| |
| |
This half ----- | | --- This half of the rope has 20 lbs of tension.
of the rope | |
has 20lbs of | |
tension | |
| |
+---+-+--+
| 40 lbs |
+--------+


For the situition that you have


|
|
O\
| \
| \
This half ------ | \ --- This half of the rope has 40 lbs of tension
of the rope has | \
40 lbs of | \
tension | \
| \
| . Anchor
+----+---+
| 40 lbs |
+--------+

No matter how you do it, in order to support the 40lb load, the sum of
all ropes attached to the load has to add up to 40lbs. If you're using
a simple pulley at the top and attach both ends of the rope to the load,
then the rope has a tension of 20lbs and both sides add up to a total
of 40 lbs. If you instead attach one end of the rope to an anchor, then
the rope has an tension of 40 lbs and the hook at the top is having to
support a total of 80 lbs.

The weight will remain quite nicely right where it is.
What is the pull on the hook?? Where did the 40 lbs go??

I hope you answer this as you do appear to know what you are talking
about. Just don't let what seems logical lead you down stray paths.
Yes, on first glance the original problem appears to need a 80 lb
strain but unfortunately it isn't true in real life. A simple test (or
reference to any physics text) will show you in less than a minute.

Harry K

In article , (Harry K) wrote:
whole bunch of snippage

To insist that there is 80
lbs when it is tied to the bottom cleat in the face of proof easily
availabe in books, on the net, even my explanations can be understood.

Cite just one book that supports your position.


Any basic physics text. If you have a Jr high student, just check one
of his science books.

Cite just one, Harry, just one.

Refusal to due a simple 1 minute test to see if your adamant stance
is correct I -do not- understand. The only thing I can figure is you
are afraid of proving yourself wrong.

READ MY POSTS, HARRY. I *HAVE*DONE*THE*TEST*ALREADY*. IT PROVES THAT YOU ARE
W*R*O*N*G.

No, you did not do it, All you have done is -say- you have and your
purported results prove you didn't.

You lie, Harry. I have done the test, and posted the truth about my results.







Harry K

Is isn't the things you know that will get you, it is what you know
that is wrong that will bite you in the ass.

Take that to heart, Harry. You're making a fool of yourself here.

If you do the test you are going to have a -very- red face.

Harry K

In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:

bunch more snippage


This part you have right but it has nothing to do with the pulley
problem.

Reread your high school physics text a few more times, until you
understand
that it is the _same_.

I do not understand you and Greg and now Steve. The test is a simple
one, anyone can do it and it will prove all three of you are wrong.
Why do you not do it. Yes, yes I know. 'I know what I know and don't
confuse me with facts'

I have done the test, Harry. It proves you wrong. Read my first post in this
thread: I began with the same preconceived notion that you did. The
difference is that when experimental results contradicted that preconceived
notion, I abandoned it, whereas you insist on clinging to it.

Ignorance - not knowing something

You began here...

Stupidity - refusing to learn when led to the source.

.. and are now here.

Do the test then get back to the thread. Also see below where I did
repeat the test using only one scale this time thus eliminating one
variation.

Harry, I really have to wonder if you have actually read ANY of the posts
that
you have responded to.

I HAVE ALREADY DONE THE TEST. IT PROVES YOU WRONG.

Shouting does not increase the believability of a lie. You didn't do
it, I have, 3 times now and every result matches what physics texts
say. Where are your diagrams and readings?

You're a proven liar, Harry.

I see you still refuse to address why you say my readings in the first
test are wrong. Oh I know why. Because it says that the strain on
the hook is 22 lbs when you just -know- it has to be 44. Your only
out is to claim error of instrument, reading or procedure.
Unfortunately it wasn't nor is it in the next two tests.

You're a proven liar, Harry. You haven't done the tests at all.

I haven't decided yet but I just may go to the local library and give
you a specific cite.

Translation: you're still trying to find a book that supports your lies.

By the way, You are the one who claimed I am
mistaken in your first or second post. By protocol it is -you- who
should be doing the research.

Go back and read the threads. I was the first to post actual test results in
this thread. You are making claims that contradict actual experimental results
and it is thus up to *you* to substantiate your claims.

Post a photo of your tests, Harry -- that's the only way anyone will ever
believe that you actually did it.

In article , (Harry K) wrote:
[big snip]
I hope you answer this as you do appear to know what you are talking
about. Just don't let what seems logical lead you down stray paths.
Yes, on first glance the original problem appears to need a 80 lb
strain but unfortunately it isn't true in real life. A simple test (or
reference to any physics text) will show you in less than a minute.


Here you go again. You haven't done any tests, and you refuse to cite any
reference works that support your claims.

Give it up, Harry.

In article , (Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
(Doug Miller) wrote in message
. com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
This is for Greg O and Doug Miller;

40
I
I
I
I
I
I
I
40

That is what you have without the second extension to the bottom
anchor. Now metally run a line from the top to a second anchor.
Have
you added anything?

Simple experiment to prove it without a scale:

Bucket with 20 or more lbs weight.
line.

Tie line to bucket and lift.

Now step on the loose end of line and pull the slack out with your
other hand.
Has the weight changed in your hand holding the bucket?

Harry K

You lost me here!!!
I don't unsderstand what slack you are refering to.
Your drawing is correct though, but what we have been discussing is
differant.
Greg
Greg

You did understand the first part?
If it is the second part, the slack I am referring to is whatever is
hanging loose leading from the hand holding the line/bucket to your
foot. In effect your line/bucket hand is the anchor at the top, your
foot is the anchor at the bottom.

What we are discussing is the -same- thing.

NO! It is *not* the same thing, because you're *holding* that rope in your

hand. That apparently "minor" difference changes *everything*.


----------------------------------------------------------------------------
Oh for gods sake. How dense are you? Here to make it -really- simple
for you which I shouldn't have had to explain. Your had is
substituting for the top anchor! Try again but make some sense.

-----------------------------------------------------------------------------

I'm obviously less dense than you, at any rate, because I can see that
whether
the rope is free to move over the top support, or fixed at the top support,
makes a difference, and you don't.

The hand is *not* substituting for the top anchor *unless* the hand does not
grip the rope, but allows it to slide through -- remember that in the
situation posed by the original poster, the segment of the rope suspending
the
weight is *not* attached to any "anchor" at the top, but merely passed
through
a hook.

It _makes_a_difference_.


I am just trying to
simplify it down to one step at a time until you can see the logic
here.

Admirable goal. But you must be careful not to alter the problem as you
simplify, and you have just altered it.
-------------------------------------------------------

Okay, show me where it has been altered. You can't do it, it is the
same problem with your hand substituting for the hook.
----------------------------------------------------

Speaking of dense... I *did* show you where it's been altered, but you won't
see it. In the original problem, the rope was free to move over the top
support, and in your erroneous simplification of it, it's not.

No matter how you try to sidestep and adamantly refuse to
accept reality, there is no 80 lbs in the the original problem.

No matter how *you* try to "sidestep and adamantly refuse to accept
reality",

equilibrium is equilibrium, and you're still wrong.

For some reason you seem to refuse to do any experiment that will show
you are wrong.

Harry, I'm beginning to think that your mind might be just a bit closed.
I've

*done* the experiment. And I thought, going in to it, the _same_ thing you

did. (Read my original post in this thread.) The experiment proved me (and

you) wrong.

================================================= =========================
I just checked all the posts I could find and I didn't find one where
you did any experiment. If you did please give me the number of the
post and I will rechcheck it.

Up until this point, I figured that you were just dense and stubborn. Now, I
have proof that you're a liar. You not only read that post, you _responded_
to
it:

http://www.google.com/groups?hl=en&l...&threadm=83Z4c.
34291%24PY.30616%40newssvr26.news.prodigy.

com&rnum=1&prev=/groups%3Fnum%3D100%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-
8%26as_drrb%3Dq%26q%3Dfiguring%2Bloads%2Bgroup%253 Aalt.home.
repair%26as_qdr%3Dw%26btnG%3DGoogle%2BSearch

I did see where you caught me on the 20 vs 40 lb on left right side
which I admitted to screwing up.

-----------------------------------------------------------------
It would cost you less than $10 to buy a scale and
cheap pulley to test it yourself.

I already have a scale. I did the experiment. You're wrong.


-----------------------------------------------------------
So do it again only give the diagram you use and the readings you get.
It will only take minute and involve only two weighings (1 for bucket
then one for strain on hook). I don't see what is keeping you from
doing it, it isn't like it'll cost you anything. It only took me a
minute to repeat the experiment this morning. Buket 26 lbs, hook 26
lbs with the bitter end of line tied off to a bottom anchor. Go ahead
and do it, don't just run your mouth until you do.
-------------------------------------------------------------

Either you're lying, or you had the rope tied off to the scale. If it's not
free to move, it's not a replication of the original problem.

I had assumed you were at least bright enough to realize the rope
would be sliding through the hand.

You weren't "bright enough" to state it, so why should anyone assume it?

Well after all your incorrect bs
and refusal to do a simple test I should have known better.

Harry, this has to be about the tenth time now: I've already done the test.

No you did -not- do the test or if you did you are lying about your
results.

Harry, *you* are a proven liar. You claimed to have never read my post
describing my test -- but you responded to it.

There is no reasonable explanation for either part of that.
Why lie about doing it or about the results when anyone with a spring
scale can prove you wrong in less than a minute. I just did -again-.

Indeed, Harry, why keep lying about it? You haven't done any tests, or you're
lying about the results. The actual experiment simply does not show what you
claim to see.

Do the experiment again and show your results. Here is mine which I
just repeated:

HOOK
scale 22 to 22.5
I
I
I
I
I
Bucket 21.5 lbs

OK, but so what? A spring scale reads 22 pounds when a 22-pound weight is
suspended from it. Big deal. What does that prove?

The scale is so short that accurate reading to even 1/2 lb is shaky.
The 22 to 22.5 depended upon how I eased the rope going over the hook,
yes it did change somewhat but not by 20 lbs.
You will find those same readings predicted in any basic physics texts
you use as a reference.

No kidding? Physics books actually predict that spring scales accurately read
weights that are suspended directly from them? Wow. Will wonders never cease?

You've been challenged repeatedly to post a citation to a physics textbook
that backs up your claims for the load on the scale in the situation described
in the original post.

You haven't done so.

Because you can't.

Your turn or are you still scared?? I don't understand adamant
refusal to do a 1 minute test.

I've done the test already. I don't understand your persistent challenge to do
something that I've already done.

If you are correct you win easily.
Just remember not to lie as anyone can check it in less than a minute.

he difference here, Harry, is that I've actually *done* the test that I
claimed to have done, and posted the results that I actually got -- unlike
you.

But just to shut you up, I did it again. Here are the particulars:

Toolbox suspended directly from the spring scale: scale reads 28 lbs. Scale is
one used for measuring the draw weight of hunting bows, and is accurate only
to within a couple of pounds -- but close enough to tell the difference
between theory and your claims, when using a 28-pound weight.

Toolbox suspended from a rope passed through the hook on the scale, and free
to move. Opposite end of rope tied to the base of a 350-pound wood shaper so
it won't move. Point of attachment of rope is 52" below the hook on the scale,
and offset 13" laterally. The rope is thus at an angle of atan(52/13) = 76
degrees. Theory predicts that the vertical component of the load in the rope
is 28 lb * sine(76) = 27 lbs thus the total theoretical vertical load on the
scale is 55 lb. The predicted load would be somewhat less than the theoretical
value, due to several factors including friction losses between the rope and
the hook of the scale, internal stretching in the rope, and inherent
inaccuracies in the scale.

The actual measured reading is 44 lbs, or 80% of the theoretical value and
certainly more than 80% of the predicted value.

According to you, Harry, it should have read 28 lbs.

You are either lying about your results, or lying about having conducted any
tests at all. It's already proven that you have lied about not reading my post
describing my test. As a _proven_liar_, Harry, the only way you can possibly
restore a shred of anything resembling credibility is to post a photograph of
your test setup.

I'm waiting to see it.