Hi everyone! Ok, so here's the problem: What would be the weight of the earth if it were on the moon (just try and imagian that :). The masses of the moon and the earth, and their radiuses, are given. I cannot see what's the trick here. There are four possible options. The one that seemed the most logical is : (GmM)/(R+r)^2 where m - moon mass, M - Earth mass, R - Earth radius, r - moon radius. But the material it's supposed to be related to is torques and moments of force... I don't see how it's related :-\ I'd be really thankful for help on how to approach this problem. Thanks! Tomer.