A schoolboy once wrote in a composition: "Christopher Columbus was a great man because he discovered America and stood an egg upright." This young scholar had thought both deeds equally amazing. On the contrary, the American humorist Mark Twain saw nothing special about Columbus discovering America: "It would have been strange if he hadn't found it there."
The other feat the great navigator had performed is not really all that marvelous. Do you know how Columbus stood an egg upright? He simply pressed it down onto a table crushing the bottom of the shell. He had, of course, changed the shape of the egg. But how can one possibly stand an egg on end without changing its shape, the navigator didn't know.
Meanwhile it is easier by far than discovering America or even one tiny island. I'll show you three methods: one for boiled eggs, one for raw eggs, and one for both.
A boiled egg can be stood upright simply by spinning it with your fingers or between your palms like a top. The egg will remain upright as long as it spins. After two or three trials the experiment should come out well.
This won't work if you try to stand a raw egg upright, you may have noticed that raw eggs spin poorly. This, by the way, is used to distinguish a hard-boiled egg from a raw one without breaking the shell. The liquid contents of a raw egg is not carried along by the spinning as fast as the shell and, therefore, sort of
damps the speed down. We have to look for another way of standing eggs and one does exist. You have to shake an egg intensely several times. This breaks down the soft envelope containing the yolk with the result that the yolk spreads out inside the egg. If you then stand the egg on its blunt end and keep it this way for a while, then the yolk, which is heavier than the white, will pour down to the bottom of the egg and concentrate there. This will bring the centre of mass of the egg down making it more stable than before.
Finally, there is a third way of putting an egg upright. If an egg is placed, say, on the top of a corked bottle and another cork with two forks stuck into it is placed on the top as shown in Fig. 17, the whole system (as a physicist would put it) is fairly stable and remains in equilibrium even if the bottle is slightly
inclined. But why don't the egg and cork fall down? For the same reason that a pencil placed upright on a finger doesn't fall off when a bent penknife is stuck into it as shown. A scientist would explain: "The centre of mass of the system lies below the support." This means that the point at which the weight of the system is applied lies below the place at which it is supported.
The other feat the great navigator had performed is not really all that marvelous. Do you know how Columbus stood an egg upright? He simply pressed it down onto a table crushing the bottom of the shell. He had, of course, changed the shape of the egg. But how can one possibly stand an egg on end without changing its shape, the navigator didn't know.
Meanwhile it is easier by far than discovering America or even one tiny island. I'll show you three methods: one for boiled eggs, one for raw eggs, and one for both.
A boiled egg can be stood upright simply by spinning it with your fingers or between your palms like a top. The egg will remain upright as long as it spins. After two or three trials the experiment should come out well.
This won't work if you try to stand a raw egg upright, you may have noticed that raw eggs spin poorly. This, by the way, is used to distinguish a hard-boiled egg from a raw one without breaking the shell. The liquid contents of a raw egg is not carried along by the spinning as fast as the shell and, therefore, sort of
damps the speed down. We have to look for another way of standing eggs and one does exist. You have to shake an egg intensely several times. This breaks down the soft envelope containing the yolk with the result that the yolk spreads out inside the egg. If you then stand the egg on its blunt end and keep it this way for a while, then the yolk, which is heavier than the white, will pour down to the bottom of the egg and concentrate there. This will bring the centre of mass of the egg down making it more stable than before.
Finally, there is a third way of putting an egg upright. If an egg is placed, say, on the top of a corked bottle and another cork with two forks stuck into it is placed on the top as shown in Fig. 17, the whole system (as a physicist would put it) is fairly stable and remains in equilibrium even if the bottle is slightly
inclined. But why don't the egg and cork fall down? For the same reason that a pencil placed upright on a finger doesn't fall off when a bent penknife is stuck into it as shown. A scientist would explain: "The centre of mass of the system lies below the support." This means that the point at which the weight of the system is applied lies below the place at which it is supported.
EPIC.AWESOME PHYSICS.WHERE DID YOU FIND IT FROM
ReplyDeleteAdu, information for this blog is taken from a book called "Fun with Maths and Physics" by Y.I. Perlman. If we get that book when I am there we will buy it.
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