threebikesmcginty
Corn Fed Hick...
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- ...on the slake
The important thing User9609 wants to know (possibly) is will there be enough to go over the turkey at Christmas
And around your spuds (ooer missus) on bonfire night.
2 Strange mathematical facts .
- Thread starter Dave7
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And around your spuds (ooer missus) on bonfire night.
I see, based on the area of an annulus presumably. Nifty and I see doing a search this is how some other people did it. I would guess based on an archimedean circle you could get the arc length which was what I was aiming for, but you wouldn't be able to measure the thickness accurately enough. If it was a seriously thick then I reckon you could and would even work for half and quarter rotations.
I'm sure people can work out what d² means for themselves. I'm not sure why you seem to be getting quite giddy in these threads but I think you should tone things down a bit as it spoils some of the more interesting things you say ;-).
[QUOTE 2091604, member: 9609"]
As for proving it right - I couldn't work out a formula so I solved it in excel - goal seek wouldn't work as there was two variables - so I made my own goal seeker in visual basics - see below
The following code builds a comparison table on a worksheet and the answers correspond identically with your formula. Column A is roll dia in mm & ColumnB is length of foil on roll.
[/quote]
Fascinating. Four different approaches to the same question .
As for proving it right - I couldn't work out a formula so I solved it in excel - goal seek wouldn't work as there was two variables - so I made my own goal seeker in visual basics - see below
The following code builds a comparison table on a worksheet and the answers correspond identically with your formula. Column A is roll dia in mm & ColumnB is length of foil on roll.
[/quote]
Fascinating. Four different approaches to the same question
.
thom
____
- Location
- The Borough
[QUOTE 2091604, member: 9609"]
As for proving it right - I couldn't work out a formula so I solved it in excel - goal seek wouldn't work as there was two variables - so I made my own goal seeker in visual basics - see below
[/quote]
Glad to help - it reminds me of the slightly weird question about circumferences:
If you had a rope going right round the world at ground level (assume perfectly spherical), it would be 40,000 km long.
If you wanted to elevate the rope 1m above the ground all the way round, how much longer would you need to make the rope ?
As for proving it right - I couldn't work out a formula so I solved it in excel - goal seek wouldn't work as there was two variables - so I made my own goal seeker in visual basics - see below
[/quote]
Glad to help - it reminds me of the slightly weird question about circumferences:
If you had a rope going right round the world at ground level (assume perfectly spherical), it would be 40,000 km long.
If you wanted to elevate the rope 1m above the ground all the way round, how much longer would you need to make the rope ?
thom
____
- Location
- The Borough
[QUOTE 2092172, member: 9609"]it is an astonishingly tiny amount 2*pi()*meters. a touch over 6meters.
[/quote]
Yes and that amount would be the same however big the earth was .
[QUOTE 2092172, member: 9609"]
On the subject of "The Earth" show someone a football and ask them to imagine its is our planet, then ask them to demonstrate where they think our atmosphere ends. Most people think it is a couple of inches - the truth is a little worrying![/quote]
Just looked to up to find an estimation of 100km for the really largest estimation for the extent of the atmosphere.
The earths radius is about 6000km so indeed you'd hardly notice it at all.
[/quote]
Yes and that amount would be the same however big the earth was .
[QUOTE 2092172, member: 9609"]
On the subject of "The Earth" show someone a football and ask them to imagine its is our planet, then ask them to demonstrate where they think our atmosphere ends. Most people think it is a couple of inches - the truth is a little worrying![/quote]
Just looked to up to find an estimation of 100km for the really largest estimation for the extent of the atmosphere.
The earths radius is about 6000km so indeed you'd hardly notice it at all.
LosingFocus
Lost it, got it again.
OK, this bit has actually made my head melt. Explain it please!
EDIT: Crap, no head back in working fashion and I've got it around it. Woah, cool.
Over The Hill
Guru
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- Ridden off into the sunset
[QUOTE 2091017, member: 9609"]As there are a few mathematically minded people on here can anyone help me out with an equation for the following problem
We have a roll of foil at work and I would like to estimate how much we have left from either the circumference or the diameter. When it s new it is 250m long, the inner diameter is 50mm and the outer diameter is 240mm. I would like some formula that would tell me how much is left from the diameter.[/quote]
Unroll foil until length exceeds Pi
Foil over Pi
Put pie in oven.
Warm it up.
Eat it.
We have a roll of foil at work and I would like to estimate how much we have left from either the circumference or the diameter. When it s new it is 250m long, the inner diameter is 50mm and the outer diameter is 240mm. I would like some formula that would tell me how much is left from the diameter.[/quote]
Unroll foil until length exceeds Pi
Foil over Pi
Put pie in oven.
Warm it up.
Eat it.
