posted by rachel .
need help with the following question. if earth has a mass of 6.0*10^24 kg and a radius 6.4*10^6 m:
a) find the change in gravitational potential energy of a meteorite of mass 150 kg as it moves from an infinite distance to the earth's surface.
b) with what speed does the meteorite strike the earth if it starts from rest?
thanks. i kinda get the answer for part (a) but (b) is mostly a problem.