Two balls, A and B, of mass m and 2m respectively, are carried to height h at constant velocity, but B rises twice as fast as A. The work the gravitational force does on B is
A) one quarter the work done on A.
B) one half the work done on A.
C) the same as the work done on A.
D) twice the work done on A.
E) four times the work done on A.

Question

Quizplus · Accepted Answer

The work done by the gravitational force is equal to the change in gravitational potential energy, which depends only on the mass and height, not on the speed. Since B has twice the mass of A, the work done on B is twice that done on A.

Two Balls, a and B, of Mass M and 2m