On 26/05/2017 21:27, Bill Wright wrote:
On 26/05/2017 14:00, The Natural Philosopher wrote:

No, Bill. the joints are tenoned and pinned . They cant pull out.

This is utterly basic.


A properly made gate or door doesn't need to stress the joints (which
are much weaker than the timber members) because the brace pushes up
against the cross members.

And translates any tendency to sag into a tension force on the top ledge.





--
Cheers,

John.

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\================================================= ================/

"Roger Hayter" wrote in message
...
Rod Speed wrote:

"Robin" wrote in message
...
On 26/05/2017 12:35, Clive George wrote:
On 26/05/2017 08:55, Robin wrote:
There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

Also the capstan.

The one with the weight hanging off rope at the top of the well?
There's
enough information there.

I had in mind the nautical capstan with 4 men and "Which man would have
to
work hardest to turn the capstan alone?" ISTM "hardest" is ambiguous
between (a) the force exerted (highest for shortest lever),

Yes, that's the obvious answer.

(b) the energy required per unit time (ditto if they walk at the same
speed - linear not angular - when walking alone),

That's not working harder.

and (c) the energy required per revolution (same for all).

If you assume the capstan has to be
pushed with a constant rotational speed

They arent normally, so that cant be assumed and
that would have been stated if it was a requirement.

then c) is right. If the man has a constant force available he is
doing more work the faster he walks so the furthest out one is
the answer. But unless the capstan has to be pushed at a constant
speed it is a bit hard to see any sensible answer for work done.

a) is the obvious answer, because with the longer
arm, you have more leverage and so don’t have to
work so hard. That’s the whole point of the arms.

On 27/05/17 00:30, John Rumm wrote:
If it were steel, then it would be better in tension - steel is stronger
that way, and not going to buckle.

Depends on whether its an open frame rather than skinned and on how
thick te steel is.

Of course steel buckles all the time.

The failure mode of most trusses is in fact buckling.


--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€�

Mary Wollstonecraft

On 27/05/2017 05:40, The Natural Philosopher wrote:
On 27/05/17 00:30, John Rumm wrote:
If it were steel, then it would be better in tension - steel is
stronger that way, and not going to buckle.

Depends on whether its an open frame rather than skinned and on how
thick te steel is.

I think you are misreading what I typed.

Of course steel buckles all the time.

The failure mode of most trusses is in fact buckling.

Which is why I was saying you can use a much thinner brace if it is in
tension. In tension you don't need to worry about it buckling. In
compression it could, and so you would need a stiffer brace to start with.


--
Cheers,

John.

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On Fri, 26 May 2017 22:19:58 +1000, FMurtz wrote:

Graham. wrote:
On Thu, 25 May 2017 11:16:16 -0700 (PDT), misterroy
wrote:

found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing

Would I be disqualified for putting a mark on the line provided,
rather than crossing out the letter corresponding to the correct answer
as instructed?


You do not need to you can see where the mark is rubbed out.

Only in about half the cases. I looked at every "Question" with a view
to answering each one and noticed that some had been marked incorrectly,
others correctly and some, seemingly not at all.

Starting with the boxes one (which is hardest to turn over?) my answers
are as follows:

C

G

M assuming diameters of tops of the LH ones = widths of the RH square
and equilateral triangular cross sectioned tanks

Q

All equal

A

O

Move to and fro

It wasn't clear what this butcher's weight question was about. I can see
three possible 'correct' answers to this one, each depending on how you
interpret what the real question is.

The previous student's rubbed out answer (V) suggests it was interpreted
as a requirement to minimise bending stress on the hanging beam. Another
interpretation of the problem is to minimise pull out forces on the
beam's anchor rods, suggesting Y as the answer. However, mention of the
*heaviest* weight strongly suggests both those answers are wrong due to
the use of "Trickery" involving common sense and observational skills in
the real world.

We know that such butchers' meathook rails are amply over-engineered for
the butcher's normal every day usage so we can exclude 'structural
integrity' issues from our deliberations (plus, any fatigue induced
failure here can be remedied without expensive and painful medical
procedures being invoked).

This just leaves us with the question of, "If I were that butcher,
carrying the heaviest lump of meat from the direction implied by that
sketch, where would I want to place it to minimise musculoskeletal wear
and tear?" The answer, quite obviously, becomes "The nearest to hand,
stupid!", in this case, Z. :-)

The only fly in the ointment with this last option is WTF didn't the
daft butcher slide all the hooks to the right hand end of the bar
beforehand? That way, he could have reduced the strain and effort on his
musculoskeletal system even further by arranging for hook V to be nearer
again, allowing him to slide the 'heaviest weight' to the far end of the
bar with even less strain and effort, leaving the remaining hooks close
to hand and available for more '(but slightly less) heavy weights'.

I may be wrong in interpreting this question as one of 'ergonomics' but
**** it all, that's the only way to make any sense of this one.

Moving onto the cups question which seems to be a question of which of
the four cups encloses a presumed identical volume of liquid with the
least amount of surface area, I'm rather drawn to B despite answers C and
D looking like they could be equally as good a choice (the 'All equal'
option is rather spoilt by A being quite obviously the one destined to
cool the fastest).

All of them (cogs question)

N

Fall

V (looks closest to the optimal 45 degree angle ignoring air resistance)

A

H

R

V

C

All equal (assuming we ignore friction effects as Galileo was able to)

N

Fall

Rise and then fall

H

L

R

W

D (as the previous student indicated, assuming a sweeping bend rather
than a tight hairpin bend where the right answer could easily be "All
equal"). Again, yet another question where I can't decide whether I'm
facing a cunningly disguised question concerned with the dangers of
making unwarranted assumptions or just very shoddy question setting.

Move in a circle

N assuming disks with holes punched in them (in which case, WTF is
causing M to remain poised in its depicted position?)

S

X (assuming equal effort on the part of the 'pushers')

Wow! Yet another imponderable question (about skiddiest car). Yet again,
we are left to make several assumptions from the very poor quality
'evidence of our eyes' but I'll give it a go.

I'm led to assume we are looking at a **** poor sketch of a snapshot
overhead view of a sharp bend or corner on a race track and further
obliged to assume a dry equally grippy road surface with no adverse
camber or rubber crum to penalise any of the cars which I'm further
obliged to assume all have equally grippy tyres and are all travelling at
the same speed in some sort of race event.

Having been forced to make all these assumptions just to drill down to
what I *think* is the core of the problem, I can only conclude that car C
is most likely to skid due to its higher rate of change of velocity
needed to negotiate the bend on a tighter radius than the other three
cars which results in higher side forces being applied to the tyres from
the resultant centripetal force.

In real life, there are many reasons why answer C will be most
emphatically wrong but, what the hey, this is just a question on a 1950's
mechanics exam paper. :-)

H

One

All equal

The mechanism will jam (I'm only 99% sure but if I'm wrong then opposite
direction unevenly becomes the only viable alternative)


I would hope that such shoddy exam question setting as exhibited by JR
Morrisby's efforts would be rejected today. However, I believe (rightly
or wrongly) that such shoddiness in examination question standards still
abounds to this day.

--
Johnny B Good

On Thu, 25 May 2017 23:52:14 +0100, John Rumm wrote:

On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing


Is the gate question a trick? H has the brace the wrong way round.

Bill
tesnd to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

The butchers hook one as well... depending what you want to achieve -
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself! :-)

Nothing else made any sense due to lack of information in regard of the
rail and its supports. One was left to make far too many completely
unwarranted assumptions about the non biological content leaving only the
biomechanical and mindset assumptions of the butcher himself as the least
contentious of all the possible assumptions that could be made from the
cunningly disguised content of that question.

If you analyse that question very closely and carefully, you'll realise
it was actually a cunningly disguised question of an ergonomically driven
common sense based solution to a problem faced by the butcher rather than
anything to do with what was least stressful to the hook rail and its
supports. Even so, it did beg the question as to why the butcher wasn't
clever enough to slide all the hooks to the right hand end of the rail
beforehand to ease the load even further but I guess this may have made
the required answer all too obvious for the examiner's liking. :-)

--
Johnny B Good

On Fri, 26 May 2017 08:55:15 +0100, Robin wrote:

On 25/05/2017 23:52, John Rumm wrote:
On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing



Is the gate question a trick? H has the brace the wrong way round.

No trick. The brace works in both compression and tension and adds the
additional stiffness against sag all the other examples were all
completely lacking.


Bill
tends to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

Oh yes indeedy! That one needed a ton of (unwarranted in real life)
assumptions to be made just to drill down to the core of the question (an
issue of which vehicle was being subjected to the highest sideways forces
on that part of the corner).


Also the capstan.

The capstan one was a straight forward "Lever Question". Nothing
complicated or tricky about it at all.

Again, far too many unknowns to decide whether R would land up working
the hardest due to an extremely light load which would make S the more
energy efficient option or whether, as was implied, that R would have to
work the hardest by virtue of greater effort to move a heavier load.

To attempt to answer on the basis of effective energy input by one
person alone at each indicated position in turn requires addressing the
issue of 'matching impedances' between the generator and the load. Whilst
it's true that the energy input by R trotting around the capstan at half
the effort is the same as T walking at half the speed but full effort,
the energy expended by R and T is unlikely to be the same.

If this question is merely a trick question where the correct answer is
deemed to be "All equal", then it falls far short of the quality of
'trick question' demonstrated by the Butcher's hook question.


The butchers hook one as well... depending what you want to achieve -
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Least distance to carry the bloody thing

Is the *right* answer! :-) (a cleverly disguised question of ergonomics
and perhaps a reminder that the human skeleton and musculature is
constrained by the same laws of 'mechanics' as apply to 'engineered'
mechanical systems.

--
Johnny B Good

On 27/05/2017 00:28, John Rumm wrote:
On 26/05/2017 21:24, Bill Wright wrote:
On 26/05/2017 18:06, John Rumm wrote:

[1] e.g. like this one I made earlier:

http://wiki.diyfaq.org.uk/index.php/...and_brace_door

In which the braces are the correct way!

Indeed. On that type of construction, it is the "right" way. For the
type pictured in the mechanics paper, it does not matter.


What's the difference?

Bill

On 26/05/2017 21:31, Rod Speed wrote:


"Bill Wright" wrote in message
news
On 26/05/2017 13:59, The Natural Philosopher wrote:


No the force has to be compression on the brace.

Bill

No Bill, It does not


Contradiction is not an argument.

But it is a statement of fact in this case.

It's actually a statement of ********.

Bill

Johnny B Good wrote
FMurtz wrote
Graham. wrote
misterroy wrote

found this test lurking in the filing cabinet at work,
some of the questions might need a bit more context.

https://drive.google.com/file/d/0B_U...ew?usp=sharing

Would I be disqualified for putting a mark on the
line provided, rather than crossing out the letter
corresponding to the correct answer as instructed?

You do not need to you can see where the mark is rubbed out.

Only in about half the cases. I looked at every "Question" with
a view to answering each one and noticed that some had been
marked incorrectly, others correctly and some, seemingly not at all.

Yeah, its obviously someone's attempt at the test that has been erased.

Starting with the boxes one (which is hardest
to turn over?) my answers are as follows:

C

G

M assuming diameters of tops of the LH ones = widths of the
RH square and equilateral triangular cross sectioned tanks

Yes, that is clearly the intention, your qualifications.

Q

All equal

A

O

Nope, H

Move to and fro

It wasn't clear what this butcher's weight question was about.
I can see three possible 'correct' answers to this one, each
depending on how you interpret what the real question is.

Yep, this is by far the poorest question.

The previous student's rubbed out answer (V) suggests it was interpreted
as a requirement to minimise bending stress on the hanging beam.

IMO it is the correct answer, because the two anchors
have to be designed to support as heavy a weight as that
on all the hooks at once when the track is fully loaded.

But then it also wouldnt matter if it
was placed on Y for the same reason.

Another interpretation of the problem is to minimise pull out
forces on the beam's anchor rods, suggesting Y as the answer.
However, mention of the *heaviest* weight strongly suggests
both those answers are wrong due to the use of "Trickery"
involving common sense and observational skills in the real world.

Mad.

We know that such butchers' meathook rails are amply
over-engineered for the butcher's normal every day
usage so we can exclude 'structural integrity' issues
from our deliberations (plus, any fatigue induced
failure here can be remedied without expensive
and painful medical procedures being invoked).

This just leaves us with the question of, "If I were that
butcher, carrying the heaviest lump of meat from the
direction implied by that sketch, where would I want
to place it to minimise musculoskeletal wear and tear?"
The answer, quite obviously, becomes "The nearest to
hand, stupid!", in this case, Z. :-)

Yours is silly because it would have to have been carried from
outside the shop to get to the rail, a much greater distance.

The only fly in the ointment with this last option is WTF didn't the daft
butcher slide all the hooks to the right hand end of the bar beforehand?

Because they dont slide that well with the heaviest
weight on them when done as crudely as in the sketch.

That way, he could have reduced the strain and effort on his
musculoskeletal system even further by arranging for hook V to be nearer
again, allowing him to slide the 'heaviest weight' to the far end of the
bar with even less strain and effort, leaving the remaining hooks close
to hand and available for more '(but slightly less) heavy weights'.

You're over wanking this one.

I may be wrong in interpreting this question as one of 'ergonomics'
but **** it all, that's the only way to make any sense of this one.

It doesnt actually make any real sense.

Moving onto the cups question which seems to be a question of
which of the four cups encloses a presumed identical volume of
liquid with the least amount of surface area, I'm rather drawn to
B despite answers C and D looking like they could be equally as
good a choice (the 'All equal' option is rather spoilt by A being
quite obviously the one destined to cool the fastest).

I assume C has curved sides to distract those who dont
really understand that its the surface area that matters.

All of them (cogs question)

N

Fall

V (looks closest to the optimal 45 degree angle ignoring air resistance)

A

H

R

V

C

All equal (assuming we ignore friction effects as Galileo was able to)

N

Fall

Rise and then fall

H

L

R

W

D (as the previous student indicated,

Nope, A because they are all lined up so A has moved the furthest.

assuming a sweeping bend rather than a tight hairpin bend
where the right answer could easily be "All equal"). Again, yet
another question where I can't decide whether I'm facing a
cunningly disguised question concerned with the dangers of making
unwarranted assumptions or just very shoddy question setting.

Nope, you've missed the important fact with this one.

Move in a circle

N assuming disks with holes punched in them (in which case,
WTF is causing M to remain poised in its depicted position?)

There will always be some friction.

S

X (assuming equal effort on the part of the 'pushers')

Nope S because he has the smallest leaver. By definition the
capstan rotates at a specific speed so my earlier comment about
WHY S is correct was wrong, it has nothing to do with the formal
definition of what work is, its all about the force required.

Wow! Yet another imponderable question (about skiddiest car).
Yet again, we are left to make several assumptions from the
very poor quality 'evidence of our eyes' but I'll give it a go.

I'm led to assume we are looking at a **** poor sketch of a snapshot
overhead view of a sharp bend or corner on a race track and further
obliged to assume a dry equally grippy road surface with no adverse
camber or rubber crum to penalise any of the cars which I'm further
obliged to assume all have equally grippy tyres and are all travelling
at the same speed in some sort of race event.

Yes, if they were different, it would have said that.

Having been forced to make all these assumptions just to drill
down to what I *think* is the core of the problem, I can only
conclude that car C is most likely to skid due to its higher rate
of change of velocity needed to negotiate the bend on a tighter
radius than the other three cars which results in higher side forces
being applied to the tyres from the resultant centripetal force.

Yes.

In real life, there are many reasons why
answer C will be most emphatically wrong

Nope.

but, what the hey, this is just a question
on a 1950's mechanics exam paper. :-)

H

One

All equal

The mechanism will jam (I'm only 99% sure but if I'm wrong

You are.

then opposite direction unevenly becomes the only viable alternative)

Nope, opposite direction evenly.

This one really sorts out those who have any real mechanical ability.

I would hope that such shoddy exam question setting as
exhibited by JR Morrisby's efforts would be rejected today.

Not a chance.

However, I believe (rightly or wrongly) that such shoddiness
in examination question standards still abounds to this day.

Corse it does.

"Bill Wright" wrote in message
news
On 27/05/2017 00:28, John Rumm wrote:
On 26/05/2017 21:24, Bill Wright wrote:
On 26/05/2017 18:06, John Rumm wrote:

[1] e.g. like this one I made earlier:

http://wiki.diyfaq.org.uk/index.php/...and_brace_door

In which the braces are the correct way!

Indeed. On that type of construction, it is the "right" way. For the
type pictured in the mechanics paper, it does not matter.


What's the difference?

The paper has pins at the joints.

"Bill Wright" wrote in message
news
On 26/05/2017 21:31, Rod Speed wrote:


"Bill Wright" wrote in message
news
On 26/05/2017 13:59, The Natural Philosopher wrote:


No the force has to be compression on the brace.

Bill

No Bill, It does not


Contradiction is not an argument.

But it is a statement of fact in this case.

It's actually a statement of ********.

Nope, and he explained why it can use compression or tension.

On 26/05/2017 22:30, The Natural Philosopher wrote:

Nevertheless Bill, you are suffering from a common complaint,. you think
that the little you do know is all there is to know.

That's exactly what you do all the time. You're notorious for it.

Those of us who
have done this for a living and studied it at university know it aint
that simple.

Oh **** me! 'I've been to Yooni so I know everything, and I certainly
know more than those guys in overalls down there on the site!' How many
times have I encountered this blinkered, arrogant attitude? Architects
who won't listen to the tradesmen being a good example.

Fact is, a guy who's spent his life making things from wood knows a damn
sight more about how to make a gate that than someone who thinks they
know everything because they're been to Yooni.

I discussed this issue with two people. One was a bloke who worked all
his life in joinery, first building wooden wagons and later in a
workshop turning out various wooden products. The other was a woman who
runs a very successful business building furniture and fitting out up-
market new houses with doors etc. Both thought the idea of making a gate
or door with the brace the wrong was round was such an elementary
mistake they wondered if I was joking. So don't give me your high and
mighty Yooni ********. I've been putting up with that ****e all my
working life and it won't wash.

Bill

On 28/05/17 05:12, Bill Wright wrote:
On 26/05/2017 22:30, The Natural Philosopher wrote:

Nevertheless Bill, you are suffering from a common complaint,. you think
that the little you do know is all there is to know.

That's exactly what you do all the time. You're notorious for it.

Those of us who
have done this for a living and studied it at university know it aint
that simple.

Oh **** me! 'I've been to Yooni so I know everything, and I certainly
know more than those guys in overalls down there on the site!' How many
times have I encountered this blinkered, arrogant attitude? Architects
who won't listen to the tradesmen being a good example.

Fact is, a guy who's spent his life making things from wood knows a damn
sight more about how to make a gate that than someone who thinks they
know everything because they're been to Yooni.

I discussed this issue with two people. One was a bloke who worked all
his life in joinery, first building wooden wagons and later in a
workshop turning out various wooden products. The other was a woman who
runs a very successful business building furniture and fitting out up-
market new houses with doors etc. Both thought the idea of making a gate
or door with the brace the wrong was round was such an elementary
mistake they wondered if I was joking. So don't give me your high and
mighty Yooni ********. I've been putting up with that ****e all my
working life and it won't wash.

Bill
yu remind me of the plumber who came to connect up my UNVENTED hot water
tank

"In the loft: great place to put it mate, it will increase your water
pressure for the showers"

He, too, did plumbing for a living.

You cling to your beliefs and myths in the face of the simple evidence
that no cantilevered structure can exist without at least one joint in
tension.

you insistence that it mustn't be the diagonal joint is simply arbitrary
and bizarre




--
€œSome people like to travel by train because it combines the slowness of
a car with the cramped public exposure of €¨an airplane.€�

Dennis Miller

Johnny B Good wrote:
On Thu, 25 May 2017 23:52:14 +0100, John Rumm wrote:

On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing


Is the gate question a trick? H has the brace the wrong way round.

Bill
tesnd to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

The butchers hook one as well... depending what you want to achieve -
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself! :-)

Alternatively, the answer could be "none of the above" as the meat clearly
already has a hook attached and he can hang it on the rail anywhere he
likes.

Tim


--
Please don't feed the trolls

On 28/05/2017 03:38, Johnny B Good wrote:


The only fly in the ointment with this last option is WTF didn't the
daft butcher slide all the hooks to the right hand end of the bar
beforehand? That way, he could have reduced the strain and effort on his
musculoskeletal system even further by arranging for hook V to be nearer
again, allowing him to slide the 'heaviest weight' to the far end of the
bar with even less strain and effort, leaving the remaining hooks close
to hand and available for more '(but slightly less) heavy weights'.

He doesn't need to he has a hook in the meat already and would just hook
it on the rail nearest him.


I may be wrong in interpreting this question as one of 'ergonomics' but
**** it all, that's the only way to make any sense of this one.

Moving onto the cups question which seems to be a question of which of
the four cups encloses a presumed identical volume of liquid with the
least amount of surface area, I'm rather drawn to B despite answers C and
D looking like they could be equally as good a choice (the 'All equal'
option is rather spoilt by A being quite obviously the one destined to
cool the fastest).

All of them (cogs question)

N

Fall

V (looks closest to the optimal 45 degree angle ignoring air resistance)

A

H

R

V

C

All equal (assuming we ignore friction effects as Galileo was able to)

N

Fall


truss answer missing here.

If the truss has been dimensioned correctly they will all have the same
strain but they may well have different loads causing that strain.

Rise and then fall

doesn't that depend on the taps being identical?
if the flow rate is slow the fall will be impossible to see even if you
know it is there.


H

L

R

W

D (as the previous student indicated, assuming a sweeping bend rather
than a tight hairpin bend where the right answer could easily be "All
equal"). Again, yet another question where I can't decide whether I'm
facing a cunningly disguised question concerned with the dangers of
making unwarranted assumptions or just very shoddy question setting.

Its the inside one assuming they depict someone going around the same
bend as you have to lean more the faster you go around the bends which
is why motorcylists scrape their knees and then fall off.


Move in a circle

N assuming disks with holes punched in them (in which case, WTF is
causing M to remain poised in its depicted position?)

The examiners hand.

S

It depends how you define work.
S would have to push hardest but travel less distance.
In reality he wouldn't be able to shift the thing as you wouldn't have
four operating positions if you only needed one man to do the job.


X (assuming equal effort on the part of the 'pushers')

Wow! Yet another imponderable question (about skiddiest car). Yet again,
we are left to make several assumptions from the very poor quality
'evidence of our eyes' but I'll give it a go.

I'm led to assume we are looking at a **** poor sketch of a snapshot
overhead view of a sharp bend or corner on a race track and further
obliged to assume a dry equally grippy road surface with no adverse
camber or rubber crum to penalise any of the cars which I'm further
obliged to assume all have equally grippy tyres and are all travelling at
the same speed in some sort of race event.

Having been forced to make all these assumptions just to drill down to
what I *think* is the core of the problem, I can only conclude that car C
is most likely to skid due to its higher rate of change of velocity
needed to negotiate the bend on a tighter radius than the other three
cars which results in higher side forces being applied to the tyres from
the resultant centripetal force.

In real life, there are many reasons why answer C will be most
emphatically wrong but, what the hey, this is just a question on a 1950's
mechanics exam paper. :-)


Looking at it C can't be turning yet or the rear wheels will hit the curb.

B is going to have to turn sharpest or he will hit A.

I would say B because he is going to have to hit the brakes to avoid A.

H

One

All equal

The mechanism will jam (I'm only 99% sure but if I'm wrong then opposite
direction unevenly becomes the only viable alternative)

doesn't the sliding pivot stop it from jamming?



I would hope that such shoddy exam question setting as exhibited by JR
Morrisby's efforts would be rejected today. However, I believe (rightly
or wrongly) that such shoddiness in examination question standards still
abounds to this day.


Well done.
have a gold star.

On Sun, 28 May 2017 11:07:10 +0100, dennis@home wrote:

On 28/05/2017 03:38, Johnny B Good wrote:


The only fly in the ointment with this last option is WTF didn't the
daft butcher slide all the hooks to the right hand end of the bar
beforehand? That way, he could have reduced the strain and effort on
his musculoskeletal system even further by arranging for hook V to be
nearer again, allowing him to slide the 'heaviest weight' to the far
end of the bar with even less strain and effort, leaving the remaining
hooks close to hand and available for more '(but slightly less) heavy
weights'.

He doesn't need to he has a hook in the meat already and would just hook
it on the rail nearest him.

Nicely spotted! :-)

If this was a question of observational skills and 'common sense' (as it
seems since it's the only way to make any sense of it), then I'm afraid
I've only got half marks (and the question setter zero marks for failing
to provide any means for the student to demonstrate the 'best answer').



I may be wrong in interpreting this question as one of 'ergonomics'
but
**** it all, that's the only way to make any sense of this one.

Moving onto the cups question which seems to be a question of which
of
the four cups encloses a presumed identical volume of liquid with the
least amount of surface area, I'm rather drawn to B despite answers C
and D looking like they could be equally as good a choice (the 'All
equal' option is rather spoilt by A being quite obviously the one
destined to cool the fastest).

All of them (cogs question)

N

Fall

V (looks closest to the optimal 45 degree angle ignoring air
resistance)

A

H

R

V

C

All equal (assuming we ignore friction effects as Galileo was able to)

N

Fall


truss answer missing here.

Oops! 'My Bad'. :-( I'm afraid I was so hung up on trying to work out
an answer to this one, I decided to 'deal with it later' and moved onto
the rest of the questions, forgetting to return to it before posting my
follow up.


If the truss has been dimensioned correctly they will all have the same
strain but they may well have different loads causing that strain.

I got as far as seeing this as a "vectors" calculation, depending on
(yet more) assumptions that the strains due to the mass of the bridge
components themselves would be insignificant enough compared to the "1
ton load" and largely balance themselves out of the equation for the
purpose of this question anyway as well assuming the structure is made up
entirely from right angled isosceles triangles.

With all those assumptions in place (all pigs prepped up and ready to
fly, so to speak), I can see that members V and X are in tension to the
tune of 0.707 tons with W and Y each carrying a 1 ton force in
compression.

It is impossible to correctly answer this question when complying with
the instruction to select "The one and only correct option" from the list
supplied since I'd want to select the *two* correct options, V and X. If
I ignore my understanding of the examiner's definition of the word
'strain' to decide the most likely singularly correct option, I'd be
forced by such logic to select 'All equal' and hope I'd correctly 'second
guessed' the examiner's definition of a 'correct answer'.

OTOH, it may simply show my ignorance of the mechanics of bridge
construction and the definition of 'strain'. :-)


Rise and then fall

doesn't that depend on the taps being identical?

No, it depends on the taps *not* being identical; in this case the LHS
tap of tank X being a much larger bore, matching the fatter pipework
allowing a faster fill rate than the smaller tap and pipework linking to
the tank on the RHS of tank X will allow it to drain away.

Rise and then fall describes exactly what will happen to the water level
in tank X during the early part of the process. Eventually, the water
levels in all three tanks will level off. The level in the LHS tank will
only fall whilst that in the RHS tank will only rise. Tank X is the only
one of the three that will exhibit this 'interesting behaviour' in the
scenario depicted.

if the flow rate is slow the fall will be impossible to see even if you
know it is there.

The question is about what happens to the water level in tank X
regardless of whether or not it can be observed. The sketch shows three,
apparently transparent tanks, along with quite obviously different sized
'taps' (valves) and plumbing to save the student from thinking up ways to
impose difficulties in arriving at a correct answer. :-)



H

L

R

W

D (as the previous student indicated, assuming a sweeping bend rather
than a tight hairpin bend where the right answer could easily be "All
equal"). Again, yet another question where I can't decide whether I'm
facing a cunningly disguised question concerned with the dangers of
making unwarranted assumptions or just very shoddy question setting.

Its the inside one assuming they depict someone going around the same
bend as you have to lean more the faster you go around the bends which
is why motorcylists scrape their knees and then fall off.

No, the ambiguity lies in the fact that the amount of lean to balance
centripetal force depends not on the speed alone but that of the velocity
change (in this case a change of velocity due to a change in direction
rather than speed).

This sketch could be a snapshot of a group of riders negotiating a
hairpin bend on a wide road where the innermost rider, D, is in fact
moving at the slowest speed but requiring the most lean to balance the
higher change of velocity due to the much tighter turn being made on the
inside of the bend. Indeed, it's just as possible to have this set up so
that all riders are travelling at the same scalar speed and show the same
succession of increasing lean angles.

This yet another badly set question wherein the only way the examiner
could have saved himself from total and utter disgrace would be by
replacing the "All equal" option with "Totally impossible to discern from
the given sketch".



Move in a circle

N assuming disks with holes punched in them (in which case, WTF is
causing M to remain poised in its depicted position?)

The examiners hand.

That lacked a smiley imho. :-)


S

It depends how you define work.
S would have to push hardest but travel less distance.
In reality he wouldn't be able to shift the thing as you wouldn't have
four operating positions if you only needed one man to do the job.


X (assuming equal effort on the part of the 'pushers')

Wow! Yet another imponderable question (about skiddiest car). Yet
again, we are left to make several assumptions from the very poor
quality 'evidence of our eyes' but I'll give it a go.

I'm led to assume we are looking at a **** poor sketch of a snapshot
overhead view of a sharp bend or corner on a race track and further
obliged to assume a dry equally grippy road surface with no adverse
camber or rubber crum to penalise any of the cars which I'm further
obliged to assume all have equally grippy tyres and are all travelling
at the same speed in some sort of race event.

Having been forced to make all these assumptions just to drill down
to
what I *think* is the core of the problem, I can only conclude that car
C is most likely to skid due to its higher rate of change of velocity
needed to negotiate the bend on a tighter radius than the other three
cars which results in higher side forces being applied to the tyres
from the resultant centripetal force.

In real life, there are many reasons why answer C will be most
emphatically wrong but, what the hey, this is just a question on a
1950's mechanics exam paper. :-)


Looking at it C can't be turning yet or the rear wheels will hit the
curb.

B is going to have to turn sharpest or he will hit A.

I would say B because he is going to have to hit the brakes to avoid A.

H

One

All equal

The mechanism will jam (I'm only 99% sure but if I'm wrong then
opposite direction unevenly becomes the only viable alternative)

doesn't the sliding pivot stop it from jamming?

I think the sliding pivot is most likely the reason it *will* jam up imo
(varying ratio of the linking bar as a lever). Now that I've had a break
from pondering this question, it seems to me to be a question of can such
a linkage without the extreme and unusual wear on the centre pin bearing
of the linkage bar even work?

Consider this; shrink the slot in the linkage bar down to a round hole
for the pivot pin bearing and you'll see straight away that such a
linkage cannot allow movement (you land up with two triangles which
cannot be contorted without bending or altering at least one of the
connecting lines. You might think turning the bearing hole in the middle
of the linkage bar into an elongated slot will help but the problem there
is that the varying lever ratios will still result in a jammed machine.

I may not have been entirely sure of my initial answer last night but,
having taken another look at the problem in the bright light of day, I'm
now convinced that the mechanism *will* jam. :-)


I would hope that such shoddy exam question setting as exhibited by
JR
Morrisby's efforts would be rejected today. However, I believe (rightly
or wrongly) that such shoddiness in examination question standards
still abounds to this day.


Well done.
have a gold star.

Thank you very much! You're so kind. :-)

--
Johnny B Good

On Sun, 28 May 2017 06:38:57 +0000, Tim+ wrote:

Johnny B Good wrote:
On Thu, 25 May 2017 23:52:14 +0100, John Rumm wrote:

On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing


Is the gate question a trick? H has the brace the wrong way round.

Bill
tesnd to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

The butchers hook one as well... depending what you want to achieve -
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself!
:-)

Alternatively, the answer could be "none of the above" as the meat
clearly already has a hook attached and he can hang it on the rail
anywhere he likes.

An excellent point! Sadly, the rules of the game, as set by the
examiner, rather precludes such an accurate answer. Indeed, this has
meant that quite a few of the other questions have also been blighted by
this same limitation. :-(

--
Johnny B Good

Johnny B Good wrote:
On Sun, 28 May 2017 06:38:57 +0000, Tim+ wrote:


Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself!
:-)

Alternatively, the answer could be "none of the above" as the meat
clearly already has a hook attached and he can hang it on the rail
anywhere he likes.

An excellent point! Sadly, the rules of the game, as set by the
examiner, rather precludes such an accurate answer. Indeed, this has
meant that quite a few of the other questions have also been blighted by
this same limitation. :-(


And yet another potentially correct answer... "It doesn't matter where he
hangs it if the bar and supports have been adequately engineered". If it
hasn't been, then it all depends on which bit of the system hasn't been
adequately engineered, the bar or the bar supports.

Tim

--
Please don't feed the trolls

The Natural Philosopher wrote:

On 28/05/17 05:12, Bill Wright wrote:
On 26/05/2017 22:30, The Natural Philosopher wrote:

Nevertheless Bill, you are suffering from a common complaint,. you think
that the little you do know is all there is to know.

That's exactly what you do all the time. You're notorious for it.

Those of us who
have done this for a living and studied it at university know it aint
that simple.

Oh **** me! 'I've been to Yooni so I know everything, and I certainly
know more than those guys in overalls down there on the site!' How many
times have I encountered this blinkered, arrogant attitude? Architects
who won't listen to the tradesmen being a good example.

Fact is, a guy who's spent his life making things from wood knows a damn
sight more about how to make a gate that than someone who thinks they
know everything because they're been to Yooni.

I discussed this issue with two people. One was a bloke who worked all
his life in joinery, first building wooden wagons and later in a
workshop turning out various wooden products. The other was a woman who
runs a very successful business building furniture and fitting out up-
market new houses with doors etc. Both thought the idea of making a gate
or door with the brace the wrong was round was such an elementary
mistake they wondered if I was joking. So don't give me your high and
mighty Yooni ********. I've been putting up with that ****e all my
working life and it won't wash.

Bill
yu remind me of the plumber who came to connect up my UNVENTED hot water
tank

"In the loft: great place to put it mate, it will increase your water
pressure for the showers"

He, too, did plumbing for a living.

You cling to your beliefs and myths in the face of the simple evidence
that no cantilevered structure can exist without at least one joint in
tension.

you insistence that it mustn't be the diagonal joint is simply arbitrary
and bizarre

Looking at how a wooden gate is made:

1. Given that you need good joints at all four corners, it is not hard
to make the top ones capable of reisting tension with no additional
work. A diagonal brace in compression needs hardly any jointing at all
as it has vertical and lateral compression forces against its trianguar
end and just needs stabilising in place with a very simple joint or
metal hardware. So you save two elaborate carpentry joints.

2. If the diagonal strut bears on the uprights as well as the
horizontals it should be possible to distribute the tension between all
four joints, and all four main members,

I am sure there is a reason why gates are made with wooden diagonals in
compression, or, as I have seen, steel cable diagonals in tension.






--

Roger Hayter

On 28/05/2017 05:01, Rod Speed wrote:


"Bill Wright" wrote in message
news
On 27/05/2017 00:28, John Rumm wrote:
On 26/05/2017 21:24, Bill Wright wrote:
On 26/05/2017 18:06, John Rumm wrote:

[1] e.g. like this one I made earlier:

http://wiki.diyfaq.org.uk/index.php/...and_brace_door


In which the braces are the correct way!

Indeed. On that type of construction, it is the "right" way. For the
type pictured in the mechanics paper, it does not matter.


What's the difference?

The paper has pins at the joints.

Pins are a weak point. They can shrink and fall out, or rot away.

Bill

On 28/05/2017 07:04, The Natural Philosopher wrote:

yu remind me of the plumber who came to connect up my UNVENTED hot water
tank

"In the loft: great place to put it mate, it will increase your water
pressure for the showers"

He, too, did plumbing for a living.

So you picked a crap plumber (probably the one who could come quickest
because he didn't have much work on) and because he was crap you feel
that you can disregard the accumulated wisdom of all tradesmen.

Bill

On 28/05/2017 19:34, Roger Hayter wrote:
The Natural Philosopher wrote:

On 28/05/17 05:12, Bill Wright wrote:
On 26/05/2017 22:30, The Natural Philosopher wrote:

Nevertheless Bill, you are suffering from a common complaint,. you think
that the little you do know is all there is to know.

That's exactly what you do all the time. You're notorious for it.

Those of us who
have done this for a living and studied it at university know it aint
that simple.

Oh **** me! 'I've been to Yooni so I know everything, and I certainly
know more than those guys in overalls down there on the site!' How many
times have I encountered this blinkered, arrogant attitude? Architects
who won't listen to the tradesmen being a good example.

Fact is, a guy who's spent his life making things from wood knows a damn
sight more about how to make a gate that than someone who thinks they
know everything because they're been to Yooni.

I discussed this issue with two people. One was a bloke who worked all
his life in joinery, first building wooden wagons and later in a
workshop turning out various wooden products. The other was a woman who
runs a very successful business building furniture and fitting out up-
market new houses with doors etc. Both thought the idea of making a gate
or door with the brace the wrong was round was such an elementary
mistake they wondered if I was joking. So don't give me your high and
mighty Yooni ********. I've been putting up with that ****e all my
working life and it won't wash.

Bill
yu remind me of the plumber who came to connect up my UNVENTED hot water
tank

"In the loft: great place to put it mate, it will increase your water
pressure for the showers"

He, too, did plumbing for a living.

You cling to your beliefs and myths in the face of the simple evidence
that no cantilevered structure can exist without at least one joint in
tension.

you insistence that it mustn't be the diagonal joint is simply arbitrary
and bizarre

Looking at how a wooden gate is made:

1. Given that you need good joints at all four corners, it is not hard
to make the top ones capable of reisting tension with no additional
work. A diagonal brace in compression needs hardly any jointing at all
as it has vertical and lateral compression forces against its trianguar
end and just needs stabilising in place with a very simple joint or
metal hardware. So you save two elaborate carpentry joints.

2. If the diagonal strut bears on the uprights as well as the
horizontals it should be possible to distribute the tension between all
four joints, and all four main members,

I am sure there is a reason why gates are made with wooden diagonals in
compression

It's always been done like that because when people have done it the
other way the gate has been less strong.

It's even in the Bible.

Nathaniel who worked for the Council came to Jesus in the tenth hour
when it was his teabreak and he did sayeth unto him, Can you maketh a
good gate for the Garden of Gethsemane? It must be a proper gate that
will gladden the hearts of all who know anything about woodwork when
they see it.
Jesus said Whence thou knowest me? Nathaniel answered I know you are a
carpenter and also the Son of God on Sundays so you aught to do a good
job.
Jesus drank of his tea and said, You had a gate for the Garden, when I
passed by there seven days ago, for I saw it with mine own eyes, though
it looked like a poor gate I must say.
Nathaniel said, That gate was as worthless as the dung that falls from a
dog, and the man who made it was a wastrel and a vagabond. For he put
the brace the wrong way round and the gate fell into many pieces, and
the pieces still lay on the ground, except for the one that I threw at
the wastrel's head.
Jesus was pleased at this chance to show his worth and become favoured
by the Council for he saw that many lucrative jobs might come unto him
by those means, so he did make a gate, and it was sturdy and fully
children proof with the brace the way His Father had ordained braces
must be.
And so the gate was good, and Nathaniel paid Jesus, and gave him a tip.
The next day when the soldiers came for Jesus to take him to Calvary
where they would kill him he pointed to the man who had made the first
gate, and said, Take that man instead of me for he cannot make a good
gate but I have made an excellent gate and it's over there if you want
to cast thine eyes over it.
The soldiers went to Jesus' gate and one said, This gate is good for
many reasons but the main one is that the brace is the right way round.
So the soldiers took the wastrel who had made the first gate and nailed
him to a cross and forgot about Jesus for the time being.
But the wastrel was the man who had made the cross on which he suffered,
for he had worked for the Council making various things, and he had put
the brace above the crossarm instead of below it, so it was in tension
instead of compression. The pins were rent asunder for the man was
exceedingly stout and the crossarm falleth to the ground, and the man
ran away.
After these events had passed Jesus became the Main Man with the
Council, so it was he who made all the crosses from then on. He made
them how his Father (and his dad Joseph) had said they should be made,
so they were exceeding strong.
So when the soldiers came again and took Jesus and nailed him to a
cross, the cross did not break, and Jesus was stuck there, and he cried
Oh God why hast thou betrayed me? and God answered, Part of thy skill
should be to know when to botch. Think about it my Son.

"Bill Wright" wrote in message
news
On 28/05/2017 05:01, Rod Speed wrote:


"Bill Wright" wrote in message
news
On 27/05/2017 00:28, John Rumm wrote:
On 26/05/2017 21:24, Bill Wright wrote:
On 26/05/2017 18:06, John Rumm wrote:

[1] e.g. like this one I made earlier:

http://wiki.diyfaq.org.uk/index.php/...and_brace_door


In which the braces are the correct way!

Indeed. On that type of construction, it is the "right" way. For the
type pictured in the mechanics paper, it does not matter.


What's the difference?

The paper has pins at the joints.

Pins are a weak point. They can shrink and fall out, or rot away.

Irrelevant to what was in the TEST.

On Sun, 28 May 2017 17:23:38 +0000, Tim+ wrote:

Johnny B Good wrote:
On Sun, 28 May 2017 06:38:57 +0000, Tim+ wrote:


Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself!
:-)

Alternatively, the answer could be "none of the above" as the meat
clearly already has a hook attached and he can hang it on the rail
anywhere he likes.

An excellent point! Sadly, the rules of the game, as set by the
examiner, rather precludes such an accurate answer. Indeed, this has
meant that quite a few of the other questions have also been blighted
by this same limitation. :-(


And yet another potentially correct answer... "It doesn't matter where
he hangs it if the bar and supports have been adequately engineered".
If it hasn't been, then it all depends on which bit of the system hasn't
been adequately engineered, the bar or the bar supports.

That's exactly the problem, Ambiguity! (and in spades!).

In fact there's so many of these ambiguously posed questions sprinkled
around where the only way the student can provide the (or most) correct
answer is by 'breaking the rules' in regard of indicating which of five
possible answers is the correct *one* that it makes me wonder whether
this (contrary to most examination papers) was designed specifically to
identify budding geniuses (or troublemakers) prepared to stand up and be
counted.

It's almost as if this was some sort of inverse precursor to "The Milgram
Experiment"[1] which was carried out in 1961 at Yale University to
examine the issue of "Obedience" which had been raised at the Nazi war
criminal trials by the defendants' claims that "They were just following
orders."

I guess it's the common factor of the deceitful nature of that
sprinkling of "Trick Questions" embedded in the exam paper that's made me
think of the Milgram Experiment which had relied entirely upon deception
to gain insight into the nature of obedience to authority figures.

In the case of this exam paper, one would prefer to think of it as a way
to identify free thinking geniuses as candidates for further educational
advancement but it could just as easily be a way to deal with potential
trouble makers by denying them access to further education. How the test
results are interpreted depends on the aims of the sponsor who may not
necessarily have taken the question setter entirely into his confidence
[2].

[1] https://www.simplypsychology.org/milgram.html

[2] Perhaps I'm overthinking this. I seem to be in danger of developing a
conspiracy theory. My apologies. If there's one thing the world isn't
running short of, it's conspiracy theories. :-(

--
Johnny B Good

On 28/05/2017 04:49, Bill Wright wrote:
On 27/05/2017 00:28, John Rumm wrote:
On 26/05/2017 21:24, Bill Wright wrote:
On 26/05/2017 18:06, John Rumm wrote:

[1] e.g. like this one I made earlier:

http://wiki.diyfaq.org.uk/index.php/...and_brace_door


In which the braces are the correct way!

Indeed. On that type of construction, it is the "right" way. For the
type pictured in the mechanics paper, it does not matter.


What's the difference?

In a framed construction, the brace is inline with the other timbers.
This means that its not easy to make a joint at the brace ends that
would work well in tension unless you are going to opt for more
difficult to construct angled M&T joints. So the expedient option is to
ensure this brace is oriented that it acts in compression like a gallows
bracket, since this puts little stress on the fixing points of the brace.

With a picket style construction like that shown in the paper, all the
joints are simply planted on top of each other and fixed with a bolt
through the faces (rather like you were bolting together three lengths
of Meccano). Unlike M&T joinery, there is no inherent ability of the
joints themselves to resist racking, everything comes down to shear
loads on the bolts caused by the triangulation. Some will be in
compression and some in tension.

You can argue in the latter case that the brace used in the "wrong"
orientation will have a failure mode with the fixing tearing out of the
end of the brace (or the bolt shearing - depending on whether the bolt
or gate material is stronger). This would be true, but in the
circumstance with the "right" orientation, you simply get the same
failure at the end of the top cross member instead. The engineering
approach will often opt for the tension brace in circumstances like this
since it can be much thinner and needs no inherent stiffness. (as
someone else mentioned, even a cable would function here). The result
being a lighter (so less self loading in the first place) and cheaper to
construct gate.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 28/05/2017 17:19, Johnny B Good wrote:
On Sun, 28 May 2017 06:38:57 +0000, Tim+ wrote:

Johnny B Good wrote:
On Thu, 25 May 2017 23:52:14 +0100, John Rumm wrote:

On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of the
questions might need a bit more context.

https://drive.google.com/file/d/0B_U...2bnN1c0U/view?
usp=sharing


Is the gate question a trick? H has the brace the wrong way round.

Bill
tesnd to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

The butchers hook one as well... depending what you want to achieve -
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Or, as I was forced to conclude, a question of ergonomics relating to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself!
:-)

Alternatively, the answer could be "none of the above" as the meat
clearly already has a hook attached and he can hang it on the rail
anywhere he likes.

An excellent point! Sadly, the rules of the game, as set by the
examiner, rather precludes such an accurate answer. Indeed, this has
meant that quite a few of the other questions have also been blighted by
this same limitation. :-(

I think one has to read the hook in the meat as being the "real" hook,
and those depicted on the rail simply being virtual hooks indication
possible positions where the real hook may be placed. Kind of like
quantum hooks, you have a hook superposition, and its only when you
collapse the wave function you get to work out where it is! ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Mon, 29 May 2017 10:39:32 +0100, John Rumm wrote:

On 28/05/2017 17:19, Johnny B Good wrote:
On Sun, 28 May 2017 06:38:57 +0000, Tim+ wrote:

Johnny B Good wrote:
On Thu, 25 May 2017 23:52:14 +0100, John Rumm wrote:

On 25/05/2017 21:34, The Natural Philosopher wrote:
On 25/05/17 21:27, Bill Wright wrote:
On 25/05/2017 19:16, misterroy wrote:
found this test lurking in the filing cabinet at work, some of
the questions might need a bit more context.

https://drive.google.com/file/d/0B_U...BuTFU2bnN1c0U/
view?
usp=sharing


Is the gate question a trick? H has the brace the wrong way round.

Bill
tesnd to work either way.

There were more than one question however where there seemed to be
insufficient information.

The car skid for example.

The butchers hook one as well... depending what you want to achieve
-
least load on the supports, then in the middle. Least bending of the
rail, then right at the end.

Or, as I was forced to conclude, a question of ergonomics relating
to
reduction of fatigue induced stress on that classic and timeless
mechanical system, the musculoskeletal system of the butcher himself!
:-)

Alternatively, the answer could be "none of the above" as the meat
clearly already has a hook attached and he can hang it on the rail
anywhere he likes.

An excellent point! Sadly, the rules of the game, as set by the
examiner, rather precludes such an accurate answer. Indeed, this has
meant that quite a few of the other questions have also been blighted
by this same limitation. :-(

I think one has to read the hook in the meat as being the "real" hook,
and those depicted on the rail simply being virtual hooks indication
possible positions where the real hook may be placed. Kind of like
quantum hooks, you have a hook superposition, and its only when you
collapse the wave function you get to work out where it is! ;-)

Brilliant! Perhaps this examination paper has been designed to spot not
only budding geniuses but geniuses with the potential to make budding
geniuses look like a bunch of cretins. Genius! :-)

--
Johnny B Good

On 28/05/2017 21:02, Rod Speed wrote:

Pins are a weak point. They can shrink and fall out, or rot away.

Irrelevant to what was in the TEST.

We've moved on from that.

Bill