Figuring loads / block & tackle theory
 

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

SNIP

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

You didn't show how attaching the rope back to bucket is in anyway
different than attaching to a separate anchor. You are still assuming
a non-existant 40 lb load. It is the same load extended to the anchor
or the bucket handle. The text book I did find did at least -mention-
the force extending through the hook but did not specifically mention
what the force was, i.e., was it 1/2 the load or the whole load.

Harry,
LOOK at the 1st diagram on this posting. The one that shows both ends
of the rope attached to the 40lb load. You'll notice that both ends have
20lbs of tension. Two rope ends at 20lbs each is capable of supporting
a 40lb load.

Now LOOK at the 2nd diagram where one end of the rope is attached to the
load and the other end is attached to an anchor. Now since there is only
one end of the rope attached to the load, that end has to have 40 lbs of
tension in order to support a 40 lb load. The other end of the rope also
has to have 40 lbs of tension in order to keep it from running out of
the pulley.

Now LOOK at the 1st diagram again. Note that the rope is under 20 lbs of
tension. Notice that the rope goes to and from the pulley for 2 force
vectors from the pulley. Each vector has 20 lbs and 2 times 20 is 40.

Once again LOOK at the 2nd diagram. Note that in this diagram the rope is
under 40 lbs of tension. Once again, notice that the rope goes to and from
the pulley for once again 2 force vectors. However, since the force vectors
are now 40lbs instead of 20lbs, the force that the top pulley is having to
support is now 40 times 2 for a total of 80 lbs.

The tension in the rope doubles when going from both attachment points on
the load to a single attachment point on the load and a single attachment
point on an anchor.

Personally, I enjoy teaching someone something and seeing the light bulb
go off when the student realizes what is going on. But, I'll forgo that
pleasure in your case since it seems that the bulb is burnt out.

If you continue to ignore what everyone else in this newsgroup continues to
say, then I can only come to one of three conclusions.

1. You're a idiot.
2. You're a liar.
3. You're a troll.

I really don't care which of the above conclusions is the correct one since
it's obvious that in all three cases the correct thing to do is to drop it
and allow you to kill yourself off (hopefully before you reproduce) by
killing yourself in the future by overloading a hoist due to your massive
ignorance of physics.

Later people.

DON'T FEED THE TROLL

Too bad. http://science.howstuffworks.com/pulley.htm

Has a diagram with all force vectors clearly labeled, 2 100 down
yeilding a 200 lb down force on the hook. Unfortunately there is also
a 100 up vector that cancels one of the up for a remaining force of
100 lbs on the hook.
Incidently I layed this same problem out for 6 different people
ranging in eduction from a masters to HS. Every one got the right
answer including a retired science teacher.

I can only hope you are not science instructor. If so, god help the
education business.

Harry K

Figuring loads / block & tackle theory
 

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

Test 2 - Rope over scale hook angle to anchor and tension eased
several times before reading. Three tries.

SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight

Readings:
bucket scale
18 21
16 21
16 21

The readings you report are not consistent with your diagram, which shows
only
one scale at the top. You purport to have made two force measurements with
only one scale. Nice trick.


WTF?? what two force measurements are you talking about now?

"Bucket" and "scale". Just like you posted. What are those?


I can't explain.
1. Where did the 18 reading come from? Anomalous but there it is and
I reported it.

Operator error.

Yes probably was but afterwards I got to thinking, due tothe angle the
scale is pulled somewhat sideways which might be causing some minor
errors.

2. Why 5 lbs more to the anchor? I know the angle changes the force
vector and thus (I assume) the reading some, but I wouldn't think 5
lbs worth. The angle (measured with a bevel gauge and then the saw
angle scale from that is:
40 degree give or take a degree.

Where are you taking this measurement? According to your diagram, you had a
*single* scale at the top. What does *that* scale show?

WTF? Try again and whow where I ever said I had more than one. I
already reported what *that* scale said. Try looking at the diagrams
and maybe understanding a few basic physic principles.

You showed two lists of measurements: "bucket" and "scale".


While doing that I ran another test. Rope was laying in the water
between times so it was now soaked.

bucket 17 scale 21 to 23 depending on how the rope was eased on the
hook.

What does the scale _at_the_top_ show, Harry? That's what we're arguing
about.
Nobody cares what the load is in the individual ropes. What's the load at the

top?


WTF redux? Show 1 time, any one time where I was measuring anything
*except* the scale at the top. Even better try showing where I
reported *any* reading of load on individual rops.

Again: you show two lists of measurements: "bucket" and "scale".

Once again the scale is crude but the readings are as I have given
them. Why would I lie? Anyone can repeat the test in a minute or
less.

Then I suggest you do the test: arrange the weight, scale, and anchor as
shown
in your diagram above and reproduced he

SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight

and report what the scale at the top reads.

Already did it 4, or was it 5, times in this one thread.

Doug I will repeat what I said before 'just how effing dense are you?'
my diagrams, each and every one of them, clearly show that the rope is
attached to the hook on the scale with the rope running over it.

And then you list two sets of measurements: "bucket" and "scale".

For
god's sake I even mentioned adjusting the tension on the hook/rope
befoe reading the scale. Just where in the hell did you -think- I was
measuring?

Can't tell from your posts just *what* you're measuring.

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:
Two cars of equal mass, both going 50 mph crash head on. Car 1 feels
a crash equal to 100 mph.

Absolutely false. You clearly understand nothing of physics.

Each vehicle decelerates in the same time and distance as it would have, had
it collided with a fixed object at 50 mph.

Hey you got it. You would be amazed at how many people don't and
refuse to believe it even when clearly explained as you have done.

Yes, I got it. You clearly don't get it, though: this contradicts your claim
that it's "equal to 100 mph".

Here is another one. My brother has 2 children, one is a girl. What
are the odds the 2nd is a girl?

One-third. Do I have to explain that one to you also?

I have now performed many experiments, listed honest results, given
you a citation showing the force vectors and all you have done is run
your mouth saying I am lying and the one citation is wrong.

Harry, you lie.

You have not yet given a single citation that supports your claims. The one
citation you give does _not_ mention the load at the top support.

How many lies does that make that I've caught you in now? Four?

End of discussion. You have proved that you can lead a horse to water
but you can't make hime drink. Enjoy your ignorance.

Bye.

Good riddance, liar. Anyone can perform the test and see that you are wrong,
and that you have lied about your results repeatedly.

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
"Greg O" wrote in message
...
"Michael Daly" wrote in message
...
On 16-Mar-2004, (Doug Miller) wrote:

You know that, I know that, Mike knows that

I can't help but notice that he hasn't responded to a single one
of my posts.

Mike

Mike, I apologize if I missed you but I don't see any in my google
reader. I just reviewed the entire list of posts and still don't see
any. If you have a point that hasn't been raised try again or put it
to one of Greg or Doug's. The only points that have been raised by
any of them all come down to -you are wrong, you are lying- and the
like. None have posted any research, only one claims to have done the
test and he lied about the results.

No, Harry, it is _you_ who is lying about results. Or about your test setups.

One or the other. The setups you purport to be measuring simply don't give
the
results you report.

We're still waiting for the photos of your setups, Harry.

And I was going to, actually was there to borrow a camera, but said
why? You will only claim I am faking.

ROTFLMAO!

Still waiting for your photos, Harry....

See my other post to Greg for a
cite. I am still looking for a better one but not holding any hopes.

That cite does *not* in any fashion support your claims.

As predicted you would say 'that is wrong' with nothing behind it.
You haven't done any research at all.

Read what I wrote, fool. I didn't say that anything on that site was wrong. I
said it doesn't support your claims. And it doesn't. Yet you continue to
falsely claim that it does.

You're a liar, Harry.

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
Douglas and Rosemarie Miller wrote in message
gy.com...
In article ,
says...
[big snip]

Someone way up thread posted at link to a site
giving the good explanation.

Once again, Harry, you're caught in a lie. The site posted does *not*
support your position here, despite your false claim that it does.
Here's the relevant part of the post you refer to:

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.

Note that last sentence, Harry: "does not adress [sic] the weight on the
hook".


And just where did I say that it did? I said that someone had posted
a link, you found it. I didn't read it.

You apparently haven't read very much of anything -- including what you
yourself have written. You said that the link was to "a site giving the good
explanation." In fact, that site doesn't explain *anything* that is relevant
to this discussion.

One citation, Harry, just *one*, of a published source that supports your
claims. Just one.

We're waiting.

See below. I gave a cite and jsut as I predicted you said it was wrong.

Harry, when are you going to stop lying?

I did _not_ say the site was wrong. I said it does not support your claims.
And it doesn't. But you continue to falsely claim that it does, even though
it never mentions the one point that we're arguing about.

You're a liar, Harry.

Figuring loads / block & tackle theory
 

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

SNIP

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

You didn't show how attaching the rope back to bucket is in anyway
different than attaching to a separate anchor. You are still assuming
a non-existant 40 lb load. It is the same load extended to the anchor
or the bucket handle. The text book I did find did at least -mention-
the force extending through the hook but did not specifically mention
what the force was, i.e., was it 1/2 the load or the whole load.

Harry,
LOOK at the 1st diagram on this posting. The one that shows both ends
of the rope attached to the 40lb load. You'll notice that both ends have
20lbs of tension. Two rope ends at 20lbs each is capable of supporting
a 40lb load.

Now LOOK at the 2nd diagram where one end of the rope is attached to the
load and the other end is attached to an anchor. Now since there is only
one end of the rope attached to the load, that end has to have 40 lbs of
tension in order to support a 40 lb load. The other end of the rope also
has to have 40 lbs of tension in order to keep it from running out of
the pulley.

Now LOOK at the 1st diagram again. Note that the rope is under 20 lbs of
tension. Notice that the rope goes to and from the pulley for 2 force
vectors from the pulley. Each vector has 20 lbs and 2 times 20 is 40.

Once again LOOK at the 2nd diagram. Note that in this diagram the rope is
under 40 lbs of tension. Once again, notice that the rope goes to and from
the pulley for once again 2 force vectors. However, since the force vectors
are now 40lbs instead of 20lbs, the force that the top pulley is having to
support is now 40 times 2 for a total of 80 lbs.

The tension in the rope doubles when going from both attachment points on
the load to a single attachment point on the load and a single attachment
point on an anchor.

Personally, I enjoy teaching someone something and seeing the light bulb
go off when the student realizes what is going on. But, I'll forgo that
pleasure in your case since it seems that the bulb is burnt out.

If you continue to ignore what everyone else in this newsgroup continues to
say, then I can only come to one of three conclusions.

1. You're a idiot.
2. You're a liar.
3. You're a troll.

I really don't care which of the above conclusions is the correct one since
it's obvious that in all three cases the correct thing to do is to drop it
and allow you to kill yourself off (hopefully before you reproduce) by
killing yourself in the future by overloading a hoist due to your massive
ignorance of physics.

Later people.

DON'T FEED THE TROLL

Too bad. http://science.howstuffworks.com/pulley.htm

Q: Where does this show the load on the support?
A: It doesn't.

Has a diagram with all force vectors clearly labeled, 2 100 down
yeilding a 200 lb down force on the hook. Unfortunately there is also
a 100 up vector that cancels one of the up for a remaining force of
100 lbs on the hook.

Dolt. You can't even count. Look at the page, Harry. It shows *three* 100-lb
vectors down and one up.

Incidently I layed this same problem out for 6 different people
ranging in eduction from a masters to HS. Every one got the right
answer including a retired science teacher.

IOW they all say you're full of beans? :-)
Or is this another one of your lies, Harry?

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
[snip]
Test 2 - Rope over scale hook angle to anchor and tension eased
several times before reading. Three tries.

SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight

Readings:
bucket scale
18 21
16 21
16 21

[snip]

To all the naysayers out there. Do the damn test and be honest about
your results.

To you, Harry, I say: do the damn test and be honest about your results. Set
it up like you show in that diagram above and report what the scale
_at_the_top_ reads. Not the readings in the individual ropes. We're not
talking about the loads in the individual ropes. That's completely
irrelevant.
The *only* point under discussion is the load _at_the_top.


And see my reply to you above. That _is_ what was measured as is clear
to anyone looking.

OK, so assuming that you mean, by these two separate lists of weights, that
when the bucket weighs 'x' the scale measures 'y' -- you're *still* left with
the task of explaining how the scale could possibly measure anything higher
than the weight of the bucket.

--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

For a copy of my TrollFilter for NewsProxy/Nfilter,
send email to autoresponder at filterinfo-at-milmac-dot-com

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:

Test 2 - Rope over scale hook angle to anchor and tension eased
several times before reading. Three tries.

SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight

Readings:
bucket scale
18 21
16 21
16 21

I can't explain.

I can.

1. Where did the 18 reading come from? Anomalous but there it is and
I reported it.

Operator error.

2. Why 5 lbs more to the anchor?

Because, you idiot, like everyone has been trying to tell you for almost a
week now, the anchor bears the load of *both* ropes -- IOW, you are wrong, and
have been from the start.

Figuring loads / block & tackle theory
 

In article ,
Harry K wrote:

SNIP...


Too bad. http://science.howstuffworks.com/pulley.htm

Has a diagram with all force vectors clearly labeled, 2 100 down
yeilding a 200 lb down force on the hook. Unfortunately there is also
a 100 up vector that cancels one of the up for a remaining force of
100 lbs on the hook.
Incidently I layed this same problem out for 6 different people
ranging in eduction from a masters to HS. Every one got the right
answer including a retired science teacher.

I can only hope you are not science instructor. If so, god help the
education business.

Harry K

Once more into the fray.

See
http://www.drlaser.org/NEWRIG-sys.html

and scroll down to figure 6.

Read the text associated with that figure. Pay close attention to the
forces upon the fixed pulleys.

Figuring loads / block & tackle theory
 

"The Other Harry" wrote in message
...
[On Wed, 17 Mar 2004 15:18:33 GMT, "Ray K."
wrote:]

Actually, you want the anchor as close as possible to the weight, not
off at an angle. When it's some distance from the weight, depending on
how the scale is attached to the ceiling (free to pivot or rigidly
fixed), the scale will also measure some portion of the horizontal
component of the rope's tension and increase its reading, something
everyone has missed so far. (I know it won't make a 2:1 difference.)

Interesting.

This seems to contradict what Michael (who seems to know
what he is talking about) said about the angle of the rope
from the hook/pulley to the cleat.

Unless I misunderstood, the more vertically down the rope
goes once it leaves the hook, the greater the load on the
hook. Alternatively, the more vertically up the rope
goes, the less the load on the hook.


Yes the angle of ther rope will make a differance, I guess I assumed no one
was pulling at large angles from vertical.
Greg

Figuring loads / block & tackle theory
 

"Harry K" wrote in message
om...
"
http://science.howstuffworks.com/pulley.htm

Best I could find on the net. Do you see the force vector arrows in
the diagram? They show 100 lbs down force on the right, 100 lbs up
force on the right and another 100 lbs down force on the left. Notice
the two 100 lbs down? Yep, that would mean 200 lbs on the hook.
But wait a minute. There is one 100 lbs -up- force. That cancels one
of the downs leaving


I guess that rope is slack then, according to the drawings. Two 100 lbs
forces, cancelling themselves out equal zero!
You cite that web page time and time again, and it does not back up your
arguement! It does not give a force at the pulley!
Greg

Figuring loads / block & tackle theory
 

Holy crap. There must be 100 posts sitting out here in this
thread. Has -nobody- a clue for the solution??

There -must- be a conclusive Coyote/Roadrunner cartoon out there
with the answer. Come on folks with the DVD's, help us out!


--
TP / Network Man __________________________________
If u want the races for free,
somebody has to pay for it. ($1 Earl)

Figuring loads / block & tackle theory
 

While not directly applicable to the configuration discussed in this
thread, the following animated link is entertaining:

http://www.walter-fendt.de/ph14e/pulleysystem.htm

Figuring loads / block & tackle theory
 

"I-zheet M'drurz" wrote in message
...

Holy crap. There must be 100 posts sitting out here in this
thread. Has -nobody- a clue for the solution??

There -must- be a conclusive Coyote/Roadrunner cartoon out there
with the answer. Come on folks with the DVD's, help us out!


LOL!!
The sad part is it has been answered, time and time again!
Greg

Figuring loads / block & tackle theory
 

"Doug Miller" wrote in message news:Q946c.35669
Read what I wrote, fool. I didn't say that anything on that site was
wrong. I
said it doesn't support your claims. And it doesn't. Yet you continue to
falsely claim that it does.

You're a liar, Harry.

I find it interesting that there are at least six people in this thread that
agree on the forces that occur in a pulley set up like we have been
disscussing. At least two more posters have stated the Harry K is wrong,
although not saying who is right. A couple of confused sorts have come
through and not sided with anyone, just muttered thier confusion and left!
At any rate that is a minimum of eight people that disagree with Harry K on
this, with NO posters on his side of the arguement!

Harry, I really think you should step back from this a re-think it all!

If it makes you feel better, I looked through my engineering books tonight,
I did find some information on pulleys and the loads created, but it is much
to lengthy and in depth to reproduce here, and probably would just add to
the confusion!
But here are referance to the books.
Engineering, An Introduction to a Creative Profession, Beakley and Leach,
third edition, copyright 1977
Statics and Strenghts of Materials, Irving J. Levinson, copyright 1971
Pick them up Harry, read the relevent sections and get back with us!
Greg

Figuring loads / block & tackle theory
 

"Greg O" wrote in message ...
"Harry K" wrote in message
om...
"
http://science.howstuffworks.com/pulley.htm

Best I could find on the net. Do you see the force vector arrows in
the diagram? They show 100 lbs down force on the right, 100 lbs up
force on the right and another 100 lbs down force on the left. Notice
the two 100 lbs down? Yep, that would mean 200 lbs on the hook.
But wait a minute. There is one 100 lbs -up- force. That cancels one
of the downs leaving


I guess that rope is slack then, according to the drawings. Two 100 lbs
forces, cancelling themselves out equal zero!
You cite that web page time and time again, and it does not back up your
arguement! It does not give a force at the pulley!
Greg

I cited once, it proves the poiint.

Bye
harry K

Figuring loads / block & tackle theory
 

wrote in message .. .
Harry K wrote:
snip Harry's trying to claim he isn't lying about his test

Sorry for you. Here is the only one I found that comes close. It is
some better than Tom's. Note that I have done the research, you
haven't.

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

Best I could find on the net. Do you see the force vector arrows in
the diagram? They show 100 lbs down force on the right, 100 lbs up
force on the right and another 100 lbs down force on the left. Notice
the two 100 lbs down? Yep, that would mean 200 lbs on the hook.

But wait a minute. There is one 100 lbs -up- force. That cancels one
of the downs leaving

Count all the forces Harry. There's _three_ 100 lb down forces, and one
100 lb up force. That's two hundred pounds down, not that you care.


You just proved you can't read a force diagram, there are 3 showing
forces on the rope legs. The site proves my point.

So bye.

snip unread as you proved you don't understand the point

Harry K

John

Figuring loads / block & tackle theory
 

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

SNIP...


Too bad. http://science.howstuffworks.com/pulley.htm

Has a diagram with all force vectors clearly labeled, 2 100 down
yeilding a 200 lb down force on the hook. Unfortunately there is also
a 100 up vector that cancels one of the up for a remaining force of
100 lbs on the hook.
Incidently I layed this same problem out for 6 different people
ranging in eduction from a masters to HS. Every one got the right
answer including a retired science teacher.

I can only hope you are not science instructor. If so, god help the
education business.

Harry K

Once more into the fray.

See
http://www.drlaser.org/NEWRIG-sys.html

and scroll down to figure 6.

Read the text associated with that figure. Pay close attention to the
forces upon the fixed pulleys.

Go do the test.

bye

Harry K

Figuring loads / block & tackle theory
 

(Doug Miller) wrote in message . com...
In article , (Harry K) wrote:
(Doug Miller) wrote in message
gy.com...
In article ,
(Harry K) wrote:
Douglas and Rosemarie Miller wrote in message
gy.com...
In article ,
says...
[big snip]

Someone way up thread posted at link to a site
giving the good explanation.

Once again, Harry, you're caught in a lie. The site posted does *not*
support your position here, despite your false claim that it does.
Here's the relevant part of the post you refer to:

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.

Note that last sentence, Harry: "does not adress [sic] the weight on the
hook".


And just where did I say that it did? I said that someone had posted
a link, you found it. I didn't read it.

You apparently haven't read very much of anything -- including what you
yourself have written. You said that the link was to "a site giving the good
explanation." In fact, that site doesn't explain *anything* that is relevant
to this discussion.

One citation, Harry, just *one*, of a published source that supports your
claims. Just one.

We're waiting.

See below. I gave a cite and jsut as I predicted you said it was wrong.

Harry, when are you going to stop lying?

I did _not_ say the site was wrong. I said it does not support your claims.
And it doesn't. But you continue to falsely claim that it does, even though
it never mentions the one point that we're arguing about.

You're a liar, Harry.

Again, I predicted you would say it doesn't you did, you didn't prove
it (you can't). so Bye

Harry K

Figuring loads / block & tackle theory
 

"Ray K." wrote in message t...
Doug Miller wrote:

Big snip


Then I suggest you do the test: arrange the weight, scale, and anchor as shown
in your diagram above and reproduced he


SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight


and report what the scale at the top reads.

Actually, you want the anchor as close as possible to the weight, not
off at an angle. When it's some distance from the weight, depending on
how the scale is attached to the ceiling (free to pivot or rigidly
fixed), the scale will also measure some portion of the horizontal
component of the rope's tension and increase its reading, something
everyone has missed so far. (I know it won't make a 2:1 difference.)

BTW, some of you referred to the How Stuff Works link,
http://www.howstuffworks.com/pulley.htm, for supposedly an authorative
explanation of pulleys (even though it doesn't address the issue here).
I see their third figure, the one with one pulley at the weight and the
other at the ceiling, as wrong. At the weight, the rope changes angle
about 60 degrees; that is, each is about 30 degrees from the vertical.
The vertical component of "each" rope's tension must be 50 pounds.
Therefore, the tension in the rope must be 50/cosine 30 = 50/.866 = 57.5
pounds.

Lesson: Don't trust even fancy websites to get simple basics right.

Yes you are correct. I didn't want to get into the angle question. I
thought about it a couple of times but just figured it would
complicate things. If you are on the 1x side of things, don't bother
talking to them. They will not believe anything that goes against
their firm beliefs.

Harry K

Figuring loads / block & tackle theory
 

"Ray K." wrote in message t...
Doug Miller wrote:

Big snip


Then I suggest you do the test: arrange the weight, scale, and anchor as shown
in your diagram above and reproduced he


SCALE
I
O
I \
I \
I \
I \
I \
I \
I Anchor
16 LB weight


and report what the scale at the top reads.

Actually, you want the anchor as close as possible to the weight, not
off at an angle. When it's some distance from the weight, depending on
how the scale is attached to the ceiling (free to pivot or rigidly
fixed), the scale will also measure some portion of the horizontal
component of the rope's tension and increase its reading, something
everyone has missed so far. (I know it won't make a 2:1 difference.)

BTW, some of you referred to the How Stuff Works link,
http://www.howstuffworks.com/pulley.htm, for supposedly an authorative
explanation of pulleys (even though it doesn't address the issue here).
I see their third figure, the one with one pulley at the weight and the
other at the ceiling, as wrong. At the weight, the rope changes angle
about 60 degrees; that is, each is about 30 degrees from the vertical.
The vertical component of "each" rope's tension must be 50 pounds.
Therefore, the tension in the rope must be 50/cosine 30 = 50/.866 = 57.5
pounds.

Lesson: Don't trust even fancy websites to get simple basics right.

Yes you are correct. I didn't want to get into the angle question. I
thought about it a couple of times but just figured it would
complicate things. If you are on the 1x side of things, don't bother
talking to them. They will not believe anything that goes against
their firm beliefs.

Harry K

Figuring loads / block & tackle theory
 

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:
"Greg O" wrote in message
...
"Harry K" wrote in message
om...
"
http://science.howstuffworks.com/pulley.htm

Best I could find on the net. Do you see the force vector arrows in
the diagram? They show 100 lbs down force on the right, 100 lbs up
force on the right and another 100 lbs down force on the left. Notice
the two 100 lbs down? Yep, that would mean 200 lbs on the hook.
But wait a minute. There is one 100 lbs -up- force. That cancels one
of the downs leaving


I guess that rope is slack then, according to the drawings. Two 100 lbs
forces, cancelling themselves out equal zero!
You cite that web page time and time again, and it does not back up your
arguement! It does not give a force at the pulley!
Greg

I cited once, it proves the poiint.

Give it up, Harry. It does *not* prove your point: it _never_mentions_ the
load at the top anchor. Anyone can look at the page and see that.

Figuring loads / block & tackle theory
 

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

SNIP...


Too bad. http://science.howstuffworks.com/pulley.htm

Has a diagram with all force vectors clearly labeled, 2 100 down
yeilding a 200 lb down force on the hook. Unfortunately there is also
a 100 up vector that cancels one of the up for a remaining force of
100 lbs on the hook.
Incidently I layed this same problem out for 6 different people
ranging in eduction from a masters to HS. Every one got the right
answer including a retired science teacher.

I can only hope you are not science instructor. If so, god help the
education business.

Harry K

Once more into the fray.

See
http://www.drlaser.org/NEWRIG-sys.html

and scroll down to figure 6.

Read the text associated with that figure. Pay close attention to the
forces upon the fixed pulleys.

Go do the test.

Harry, the test has been done. And the test proves you wrong.

And don't tell us that you've done the test, and it proved you right. Your
posts are archived in Google, and they show that you simply didn't tell the
truth. Example:

http://www.google.
com/groups?q=g:
thl890848697d&dq=&hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&selm=751f8d35.0403150836.
68215d5e%40posting.google.com&rnum=117

reproduced in part he

[begin quote]
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
[end quote]

This is just plain false, Harry. Anybody can repeat this test, and see for
himself that when configured the way you show it, the reading is quite far
from what you claim it to be. Either your diagram is false, or your numbers
are false, or you never did the test.

Figuring loads / block & tackle theory
 

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:
Douglas and Rosemarie Miller wrote in message
gy.com...
In article ,
says...
[big snip]

Someone way up thread posted at link to a site
giving the good explanation.

Once again, Harry, you're caught in a lie. The site posted does *not*
support your position here, despite your false claim that it does.
Here's the relevant part of the post you refer to:

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.

Note that last sentence, Harry: "does not adress [sic] the weight on
the
hook".


And just where did I say that it did? I said that someone had posted
a link, you found it. I didn't read it.

You apparently haven't read very much of anything -- including what you
yourself have written. You said that the link was to "a site giving the
good
explanation." In fact, that site doesn't explain *anything* that is
relevant
to this discussion.

One citation, Harry, just *one*, of a published source that supports your
claims. Just one.

We're waiting.

See below. I gave a cite and jsut as I predicted you said it was wrong.

Harry, when are you going to stop lying?

I did _not_ say the site was wrong. I said it does not support your claims.
And it doesn't. But you continue to falsely claim that it does, even though
it never mentions the one point that we're arguing about.

You're a liar, Harry.

Again, I predicted you would say it doesn't you did, you didn't prove
it (you can't). so Bye

Harry, it's time to seek professional help.

Figuring loads / block & tackle theory
 

In article , (Harry K) wrote:

I am signing off to all the correspondents as you have all proved you
will not accept anything, not even valid citations that go against
your beliefs.

What "valid citations" are you talking about? The *only* citation you've ever
made is to a site that does not address the point we're arguing about!

You keep saying that "any physics book" will support your claims. So cite one,
Harry, just one.

We're waiting.

Still waiting for photos of your test rig, too. Post them in
alt.test.binaries, remember?

Figuring loads / block & tackle theory
 

I am a heating and AC guy. I installed furnaces for about three years.

And I wish you would leave enough of the original question so that we would
know WHAT is wrong. Harrry K has written at least four or five posts under
this header. We have simply no way to know which of his four or five posts
are being contradicted, here.

--

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


"Michael Daly" wrote in message
...
On 14-Mar-2004, (Harry K) wrote:

ask a physics
teacher

I'm an engineer, I was a physics teacher in grad school and
you are wrong.

Mike

Figuring loads / block & tackle theory
 

I may someday find a spring scale and try this out. Curiosity is getting to
me.

--

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


"Harry K" wrote in message
m...

"Greg O" wrote in message
...


Stormy, you have proven again, without a doubt that you do not know what
you
are talking about!

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.

Teh best you can hope for is an F

Harry K

A sig I saw somewhe
Two bad stupidity isn't painful. At least ignorance can be cured if
one wants to learn.

Harry K

Figuring loads / block & tackle theory
 

Harry K wrote:
wrote in message .. .
Harry K wrote:
snip Harry's trying to claim he isn't lying about his test

Sorry for you. Here is the only one I found that comes close. It is
some better than Tom's. Note that I have done the research, you
haven't.

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

Best I could find on the net. Do you see the force vector arrows in
the diagram? They show 100 lbs down force on the right, 100 lbs up
force on the right and another 100 lbs down force on the left. Notice
the two 100 lbs down? Yep, that would mean 200 lbs on the hook.

But wait a minute. There is one 100 lbs -up- force. That cancels one
of the downs leaving

Count all the forces Harry. There's _three_ 100 lb down forces, and one
100 lb up force. That's two hundred pounds down, not that you care.

You just proved you can't read a force diagram, there are 3 showing
forces on the rope legs. The site proves my point.

So bye.

snip unread as you proved you don't understand the point

Aha, so you read it and found that it refuted your position so clearly
that you couldn't keep on with your nonsense, huh? That's good, I was
hoping that someone could finally get through to you and I'm glad it was
me. Carry on with your pointless denials to try and save face. My job
here is done.


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

Figuring loads / block & tackle theory
 

In article , "Stormin Mormon" wrote:
I may someday find a spring scale and try this out. Curiosity is getting to
me.

Actually, Stormy, you don't even need a spring scale. All you need is
something heavy (a loaded toolbox works quite well), a pulley, and some rope.
First pick up the toolbox and set it down again so you get a feel for how
heavy it is. Next, cut off a little of the rope to make a handle for the
pulley. Tie one end of the rest of the rope to the toolbox handle, pass the
rope through the pulley, then stand on the other end of the rope. Now pick up
the toolbox by lifting the pulley. You'll feel the difference, believe me.
It's not very scientific, I know, but you will be convinced.

Figuring loads / block & tackle theory
 

Figuring loads / block & tackle theory
 

Harry: While you're at the apologizing, look up "abject" in your dictionary
and see if you don't want to rephrase your apology! LOL!!

Dave


"Harry K" wrote in message
om...
(Doug Miller) wrote in message
om...
In article , "Stormin
Mormon" wrote:
I may someday find a spring scale and try this out. Curiosity is
getting to
me.

Actually, Stormy, you don't even need a spring scale. All you need is
something heavy (a loaded toolbox works quite well), a pulley, and some
rope.
First pick up the toolbox and set it down again so you get a feel for
how
heavy it is. Next, cut off a little of the rope to make a handle for the
pulley. Tie one end of the rest of the rope to the toolbox handle, pass
the
rope through the pulley, then stand on the other end of the rope. Now
pick up
the toolbox by lifting the pulley. You'll feel the difference, believe
me.
It's not very scientific, I know, but you will be convinced.

My abject apologies to everyone involved in this fiasco. Most
especially I apologize to Doug, he had it nailed all the way. What
brings me to this?
I had to rig an exercise machine for my leg - cable thru pulleys to a
weight. After finishing, I decided to use it as one final test. This
is the only bright thing I did in the entire thing. It showed clearly
that you all were right. Now just how could I have been doing tests
and getting the reading I was that showed I was right. As Doug said,
operator error. But that wasn't enough for me. When I set out to be
stupid, just one isn't enough, I had to pile stupidity on stupidity.

1. Being absolutely certain I was right, thus believed my test
results.
2. Poor choice of tools. They were perfectly adequate but a better
scale would have showed the error.
3. Error in setting up the test.
4. Not recognizing (or even thinking) about the error even after *I*
posted it in plain English.

As stated I ran one test on a good set-up. It showed that indeed the
hook stress is 2x the weight. Returned to my orginal set-up (crude)
and stared at it, still didn't see it. Went shopping (50 mile drive)
thinking about it before it dawned. The set-up/tool error came down to
the scale. It only read to 25 lbs. If you recall my test results, my
weight was (I think) 22 lbs. I kept lowing it in two or 3 steps down
to 16 lbs.
At 16 lbs I posted that the errors I was seeing (only slight
variations from what I expected to see) "could have been that I was
measuring at the top of the scale" and also mentioned that the scale
was only 25 lb. This should have tipped me. I am rather surprised in
retrospect that none of you called me on it as you are one bright
bunch. Of course I was getting the results I expected. The
scale/weight I was using would not allow any other result. 22 lbs is
almost top scale thus couldn't possibly show a reading over 1x much
less 2x. 16 lbs was still way to much but did allow enough to give a
clue. I didn't spot it. I wonder if I would have seen it if I had
dropped the weight to 12 lbs. Somehow on my crude set-up I suspect I
would have found a way to rationalize it.

Again, my abject apologies to all but especially to Doug.

Harry K

Figuring loads / block & tackle theory
 

In article , "Dave" wrote:
Harry: While you're at the apologizing, look up "abject" in your dictionary
and see if you don't want to rephrase your apology! LOL!!

Dave

Oh, I dunno. My dictionary gives sense (3) as "shamelessly servile".
Overstates the case, perhaps, but fits. :-)


"Harry K" wrote in message
. com...
(Doug Miller) wrote in message
. com...
In article , "Stormin
Mormon" wrote:
I may someday find a spring scale and try this out. Curiosity is
getting to
me.

Actually, Stormy, you don't even need a spring scale. All you need is
something heavy (a loaded toolbox works quite well), a pulley, and some
rope.
First pick up the toolbox and set it down again so you get a feel for
how
heavy it is. Next, cut off a little of the rope to make a handle for the
pulley. Tie one end of the rest of the rope to the toolbox handle, pass
the
rope through the pulley, then stand on the other end of the rope. Now
pick up
the toolbox by lifting the pulley. You'll feel the difference, believe
me.
It's not very scientific, I know, but you will be convinced.

My abject apologies to everyone involved in this fiasco. Most
especially I apologize to Doug, he had it nailed all the way. What
brings me to this?
I had to rig an exercise machine for my leg - cable thru pulleys to a
weight. After finishing, I decided to use it as one final test. This
is the only bright thing I did in the entire thing. It showed clearly
that you all were right. Now just how could I have been doing tests
and getting the reading I was that showed I was right. As Doug said,
operator error. But that wasn't enough for me. When I set out to be
stupid, just one isn't enough, I had to pile stupidity on stupidity.

1. Being absolutely certain I was right, thus believed my test
results.
2. Poor choice of tools. They were perfectly adequate but a better
scale would have showed the error.
3. Error in setting up the test.
4. Not recognizing (or even thinking) about the error even after *I*
posted it in plain English.

As stated I ran one test on a good set-up. It showed that indeed the
hook stress is 2x the weight. Returned to my orginal set-up (crude)
and stared at it, still didn't see it. Went shopping (50 mile drive)
thinking about it before it dawned. The set-up/tool error came down to
the scale. It only read to 25 lbs. If you recall my test results, my
weight was (I think) 22 lbs. I kept lowing it in two or 3 steps down
to 16 lbs.
At 16 lbs I posted that the errors I was seeing (only slight
variations from what I expected to see) "could have been that I was
measuring at the top of the scale" and also mentioned that the scale
was only 25 lb. This should have tipped me. I am rather surprised in
retrospect that none of you called me on it as you are one bright
bunch. Of course I was getting the results I expected. The
scale/weight I was using would not allow any other result. 22 lbs is
almost top scale thus couldn't possibly show a reading over 1x much
less 2x. 16 lbs was still way to much but did allow enough to give a
clue. I didn't spot it. I wonder if I would have seen it if I had
dropped the weight to 12 lbs. Somehow on my crude set-up I suspect I
would have found a way to rationalize it.

Again, my abject apologies to all but especially to Doug.

Harry K