The speed of falling objects
 Question: Four hundred years ago, the Italian scientist Galileo Galilei claimed that in the absence of any atmosphere, all bodies on earth (e.g. a hammer and a feather) would fall to the ground in the same speed, since there would be no air resistance. Watch this youtube video, taken by the Apollo 15 astronauts who landed on the moon (in 1971). Now imagine a planet (called “Planet X”) in which the same experiment is performed, with the result that the hammer reaches the ground before the feather. What would you deduce about Planet X?
0 People tried to answer this question

 That Planet X, like the earth and contrary to the moon, has a non-negligible atmosphere, therefore the feather falls slower than the hammer.
 That Planet X is very far from the earth and the moon, therefore the laws of physics are different there.
 That Planet X must be bigger than the earth, and much bigger than the moon, therefore it exerts a very strong force on the hammer, causing it to fall faster (since it is heavier than the feather).
 That very strong winds blow on Planet X, driving the hammer underneath the feather.

1.  Klein Oded (2014-12-20 15:00:00)
The speed of Falling Objects
The subject is very interesting.

There is a direct connection between question and answers, including the Map point and specially the Apollo Film.
The question is related to earth atomspher and the infulence on falling objects. the film is related to that.

I have add another film directly related to your question which emphasis the influence of air, opposite to vacuum.

# Brian Cox visits the world's biggest vacuum chamber - Human Universe: Episode 4 Preview - BBC Two

2.  Fatelevich Aiala (2014-12-20 15:00:00)
Hi Mi

The subjects is interesting .

The two films and the point on the map are related.

I think that you could add some scientific information a bout the phisycs of those experiments.  Here is a link that can  give this information.

http://www.physicsclassroom.com/class/1Dkin/u1l5a

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