Engineers of the SMB question



Spenny said:
Use bathroom scales or if a Jammy Dodger has a higher resistance to compression than I expect a Weigh Bridge. Place a metal plate of known weight on top of the aforementioned dodger and add weight until collapse. Convert the measurement taken using Google.
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This is close to what I'd recommend.

Bathroom scales, but just put your foot on top of the jammy dodger and press it down with gradually increasing force, keeping an eye on the scales for what it reaches at the moment the jammy dodger disintegrates.
 
fyl2u said:
This is close to what I'd recommend.

Bathroom scales, but just put your foot on top of the jammy dodger and press it down with gradually increasing force, keeping an eye on the scales for what it reaches at the moment the jammy dodger disintegrates.
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Thanks, best answer so far.

I did consider getting a large square of wood, putting a jammy dodger on each corner and then it allows us to pile on a lot more weight. The 30kg of free weights on a bench on a biscuit was getting a bit dangerous! Clearly the load would be shared but you then divide the crush weight by four. I did picture the whole family standing on the board then having to consider to invite some neighbours round to help.
Flared Hicks said:
Surely the bottom chocolate button would be crushed to dust by the time 127.5 billion of its brethren were heaped on it?
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It would and also with a domed top, it would be difficult to stack. This is what lead us to consider something with a more regular shape that you could stack. The ambient temperature has a much greater effect on chocolate too. Under pressure, the temperature of a chocolate button would increase, which would decrease it's compressive strength. I think that comes into more advance science for my 8 year old for now, especially when there is a serious biscuit problem to be solved.
Unbalanced Views said:
Place the Jammy Dodger on a flat surface, but a large plastic container of some sort on top and slowly fill with water until it is crushed, measure the quantity of water in litres, a litre of water weights 1KG (give or take) - weigh a Jammy Dodger, divide the crush weight by the Dodger weight, giving you the number of Dodgers you could theoretically stack up before the bottom one is crushed
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That is effectively what we did, only with weights rather than water. It was still intact after 30Kg and 30L of water is getting to be a pretty large amount. We would need a waterbut or something.
Cockney Mackem said:
a) Did you take into account the need for your chocolate button tower to the moon to be wider at the base than at the top?

b) Do you fancy building a bridge from Scotland to Northern Ireland for Boris?
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a) No, just straight up. I should say a height of 127.5 billion buttons, not total for something 'practical'

b) It would make the border problem harder. However if it was only Boris crossing it, then I'm sure balsa would be the ideal material for the middle section. That could solve a few problems.
 
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DaveH said:
We had a daft conversion with the kids about how high you could build towers out of various food stuff. E.g. how many chocolate buttons piled up to reach the moon (127.5 billion we worked out).

On the subject of jammy dodgers you get the problem that once you add a certain weight, it would collapse. We set out to try and work out how much weight a jammy dodger could take by sticking one on the bench, putting a glass mat on the top and piling weights on top of that. As you would expect, the jam squashed quickly but we managed 30Kg with the biscuit still intact. When we took the mat of the top, it then crumbled. We had run out of weights.

Can anyone think of a way to measure the compressive strength of a jammy dodger? I do have a workshop vice I could use to crush one between two bits of wood, but that would not measure the force applied.
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If you have a vice put the said biscuit between two bits of wood the same size as the said biscuit.
Place that wood biscuit wood sandwich in the jaws of the said vice with your bathroom scales between one jaw and one piece of wood (you can add another piece of wood to protect the scales if you wish).
Turn the handle of the vice until the cookie crumbles taking note of the reading on the scales.

I am an engineer.
 
DaveH said:
We had a daft conversion with the kids about how high you could build towers out of various food stuff. E.g. how many chocolate buttons piled up to reach the moon (127.5 billion we worked out).

On the subject of jammy dodgers you get the problem that once you add a certain weight, it would collapse. We set out to try and work out how much weight a jammy dodger could take by sticking one on the bench, putting a glass mat on the top and piling weights on top of that. As you would expect, the jam squashed quickly but we managed 30Kg with the biscuit still intact. When we took the mat of the top, it then crumbled. We had run out of weights.

Can anyone think of a way to measure the compressive strength of a jammy dodger? I do have a workshop vice I could use to crush one between two bits of wood, but that would not measure the force applied.
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I’m peckish
 
EchoMan said:
If you have a vice put the said biscuit between two bits of wood the same size as the said biscuit.
Place that wood biscuit wood sandwich in the jaws of the said vice with your bathroom scales between one jaw and one piece of wood (you can add another piece of wood to protect the scales if you wish).
Turn the handle of the vice until the cookie crumbles taking note of the reading on the scales.

I am an engineer.
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To protect it from the biscuit crumbs?
 
EchoMan said:
If you have a vice put the said biscuit between two bits of wood the same size as the said biscuit.
Place that wood biscuit wood sandwich in the jaws of the said vice with your bathroom scales between one jaw and one piece of wood (you can add another piece of wood to protect the scales if you wish).
Turn the handle of the vice until the cookie crumbles taking note of the reading on the scales.

I am an engineer.
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Hmm, I like it, thanks
 
DaveH said:
We had a daft conversion with the kids about how high you could build towers out of various food stuff. E.g. how many chocolate buttons piled up to reach the moon (127.5 billion we worked out).

On the subject of jammy dodgers you get the problem that once you add a certain weight, it would collapse. We set out to try and work out how much weight a jammy dodger could take by sticking one on the bench, putting a glass mat on the top and piling weights on top of that. As you would expect, the jam squashed quickly but we managed 30Kg with the biscuit still intact. When we took the mat of the top, it then crumbled. We had run out of weights.

Can anyone think of a way to measure the compressive strength of a jammy dodger? I do have a workshop vice I could use to crush one between two bits of wood, but that would not measure the force applied.
Click to expand...

The moon has less gravitational attraction than earth, therefore it might be easier to take your biscuits to the moon first and then build your tower towards earth from there. Always assuming that the astronauts don't eat all of the biscuits.
 
RTGAdmin said:
The moon has less gravitational attraction than earth, therefore it might be easier to take your biscuits to the moon first and then build your tower towards earth from there. Always assuming that the astronauts don't eat all of the biscuits first.
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Good point actually. At a given distance between the earth and the moon, the gravitational pull will be equal and the biscuit be perfectly suspended.
 
Kevj said:
Good point actually. At a given distance between the earth and the moon, the gravitational pull will be equal and the biscuit be perfectly suspended.
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Ah, the good old Lagrange Point. I've always felt that dear Joseph-Louis should have a biscuit named after him.
 
muggboots said:
That's only 58 years worth of production, ask them.
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I could believe that. We bought a few of the crisp bag sized packs of buttons and counted to work out the average number of buttons per packet, before measuring. We were surprised to find each packet had exactly 100 buttons.
 

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