Two identical balls are at rest and side by side at the top of a hill. You let one ball, A, start rolling down the hill. A little later you start the second ball, B, down the hill by giving it a shove. The second ball rolls down the hill along a line parallel to the path of the first ball and passes it. At the instant ball B passes ball A:
A) it has the same position and the same velocity as A.
B) it has the same position and the same acceleration as A.
C) it has the same velocity and the same acceleration as A.
D) it has the same displacement and the same velocity as A.
E) it has the same position, displacement and velocity as A.

Question

Quizplus · Accepted Answer

At the instant ball B passes ball A, both balls are at the same position on the hill, meaning they are subject to the same slope and gravitational forces, thus they have the same acceleration. However, since ball B was given a shove and passes ball A, their velocities are different at the passing moment.

Two Identical Balls Are at Rest and Side by Side