Firstly, please could you forgive me if what I'm asking is stupid; I'm only just starting out on A-level Physics/Maths so I'm hardly anything of a scientist yet.(adsbygoogle = window.adsbygoogle || []).push({});

I've seen video clips in class of a NASA experiment on the moon which involved dropping a feather and a hammer. Of course, there's no air resistance there, so they both fall at the same rate, Newton's second law gives that. But then there's momentum, which is the product of mass and velocity. If the masses of the two objects are obviously different, then mv will too be obviously different (v = velocity, m = mass). I just can't get my head around the fact that the objects hit the lunar surface with different momenta, given the conditions.

Whilst typing this I thought about the Moon moving more towards the heavier object - just an exceptionally small distance, femto- maybe even zeptometres (10^-21m). Is this true?

Thanks a lot

Ash

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Momentum / gravity problem

**Physics Forums | Science Articles, Homework Help, Discussion**