Assume the moon is a perfect sphere and a straight tunnel has been drilled through the center. How long would it take a 1kg ball dropped from one end of the tunnel to reach the center? Ignore all resistances.

If a second 1kg ball is dropped 10 seconds after the first one, when and where in the tunnel would they first meet?

Idealized Moon Stats:
- Diameter: 3480 kilometers
- Mass: 7.38x10^22 kilograms (uniform density)

I read a similar bit about the Earth and with that thought experiment the time required to fall to the center is about 21 minutes. Should the moon require a longer or shorter time? And why?

Added by Edit:  Also, my undersanding is that acceleration due to gravity is not determined by mass. Mass determines relative weight due to gravity, and which of two masses affects the other mass more and from what distance.

Added by Second Edit: I believe Charlie is correct about the period being the same as the period required for a low orbit. So, why not just calculate the orbit time?

Also, the second ball dropped 10 seconds after the first ball, should contact the first ball 5 seconds from the opposite surface. So, what's the initial distance either ball falls?

Edited on November 23, 2004, 12:56 am

Edited on November 23, 2004, 1:20 am

Posted by CeeAnne on 2004-11-23 00:28:37