An asteroid of mass 1.00 x 10^9 kg comes from deep space and fallstoward Earth. Assume the asteroid started the fall from rest veryfar from Earth, and find
a) the change in potential energy when it reaches a point 4.00 x10(8) m from Earth (that's just beyond the Moon);
b) the work done by gravity during this motion;
c) the speed of the asteroid at that point; and
d) how much work would have to be done on the asteroid by someother agent so the asteroid would be traveling at only half thespeed found in (c) at the same point?