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Killer Bread

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Neil306 | 23:16 Mon 06th Feb 2012 | Science
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A friends daughter asked me the following question and now I am intrigued . . . . . If you dropped a slice of bread from a plane at 30,000 feet will it kill somebody if it landed on their head?
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No, too much wind resistance the terminal speed would be far too low.
It would also 'tumble' thus lowering the speed even more.
Something like a slice of bread would reach maximum speed after around 10 feet. Dropped from a 1st floor window or from 30,000 ft the final speed would be the same. to get a high terminal velocity you need something streamlined like...
23:32 Mon 06th Feb 2012
No.
The more pressing question should be what side down would it land?
If you open the plane door at 30000ft though to throw it out there will be probably be some damage to the occupants of the plane
Difficult to say; at 30,000 feet it would probably freeze solid so it depends how much it would thaw out as it got lower.
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Hmmm. That is an interesting twist Howard
Crusty loaf of soft?
Always glad to add a little clarity.
No, too much wind resistance the terminal speed would be far too low.
It would also 'tumble' thus lowering the speed even more.
Something like a slice of bread would reach maximum speed after around 10 feet. Dropped from a 1st floor window or from 30,000 ft the final speed would be the same. to get a high terminal velocity you need something streamlined like a dart, even a bullet would 'tumble' and have a lower velocity.
If that skydiver who is about to attempt a altitude record and his parachute fails to open after travelling faster than the speed of sound he could make an enormous hole in the ground something that wouldn't be possible if jumping from a lower height. If the slice of bread was edge way on then the wind resistance would be far less and could do more damage.
Why don't we serious injuries or damage then from when high flying birds die and fall out of the sky?
Rov, the terminal velocity for a person wearing clothing is about 120 mph at the air density found near the ground, so he will just slow down more the lower he gets and will make the same size dent as any other skydiver whose parachute fails to open. Re. the slice of pread falling edge on, it just would not happen, it would fall like a leaf because of it's aerodynamic properties.
I had a look at calculating terminal velocity and suprisingly there were no set paramaters for a slice of bread.

So I estimated weight/surface rea etc.. and it came out at about 22 mph for terminal velocity.

Judging by that I think apart from a few crumbs in your hair I'm sure you'll survive.
Johne, I presume that your calculations were based on it falling butter side down?
Unless its Dwarf bread the Pratchett fans will understand that one
Anybody got access to a tall building, there is a serious need for a bit of empirical research. If we timed the fall from various floors we could determine the terminal velocity either by observation or extrapolation.
would it change with different densities a slice of pumpernickel is moist and dense and for a given volume is much heavier than your warburtons white toastie for example
It really depends on what has been spread on the bread.
if its dwarf bread your dead

i can get up on the roof here, not sure how high it is though, highish.....
If Tesco 3 day old "freshly-baked" bread hit your house you would have no roof left.
My mums fairy cakes would kill dropped from 20 feet

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