Calculating weight & accelleration due to gravity on other planets... Help please!

[benji]

Alright, well this problem was too hard to explain, so I just decided to scan it ;).

Here's the problem:
http://img108.exs.cx/img108/5815/approb.gif

I'm pretty sure I'll be able to figure out everything else once I get part (a). But I don't know where to start with this.

Thanks.

[Galileo]

You're given:
R_{Mars}=0.53R_{Earth}
M_{Mars}=0.11M_{Earth}
(radius and mass respectively).

The acceleration at the surface of a planet canbe obtained by Newton's law of gravitation:
F=G\frac{mM}{r^2}
since F=ma, the acceleration an object undergoes a distance R from the center is:
a=G\frac{M}{R^2}.

[benji]

Ahh!

Thank you very much Galileo.