Feb 15, 2010

Question Two: An Oldie but a Goodie.

Question 2) If you drop two items from the same hight one is made of hollow glass and the other is made form solid gold which will hit the ground first?

Almost everyone knows this one. Most of us had this in school and it is very counter intuitive. To answer the questions all items fall in gravity at the same rate. Then why do some things fall differently? that is where the medium that the item is moving through comes into play. Basically lighter objects or objects that have less mass, are more affected by the friction generated by the medium. Take for instance  a balloon compared to a marble. Now lets use a balloon that is the same weight as a marble, yes it will be a big balloon. Drop them from the same hight and what happens? The marble drops like a, well, stone, straight down. Now drop the balloon. It will fall slowly maybe even drift side to side, but will take forever to reach the ground. Now they both weigh the same, so what is going on here.
The balloon has a huge surface area compared to the marble, so it has contact with much more of the medium it is travailing through. Therefor the friction in the air will affect the balloon to a much greater degree than the marble. To really see the difference pop the balloon and then drop it. Quite a bit of difference.
So the question should be; Which item will hit the ground first if dropped in a vacuum.

For conformation on this please refer to the Apollo program, this very experiment was done with a feather on the moon.

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