if an object's mass is increased, will it orbit faster or slower if the radius of its orbit does not change?

Depending on how the continental plates move it can cause a continental scale shift.

Ke reqd to move from 0 to 50 will be proportional to 50x50 or 2500. this is equal to w.  to change vel from 50 to 150 you need energy prop to 22500 - 2500 = 20,000. this corresponds to 8w.  best answer is a) . work reqd is prop to velocity squared.