A ball gains speed while rolling down a hill due mainly to
A)its rotational inertia.
B)its angular acceleration.
C)a balanced torque.
D)an unbalanced torque.

Question

Quizplus · Accepted Answer

The ball gains speed while rolling down a hill due mainly to an unbalanced torque. This unbalanced torque is created by the gravitational force, which pulls the ball downward, and the contact force between the ball and the surface of the hill, which pushes the ball forward. As a result, the ball experiences a net torque, which causes an angular acceleration that increases the ball's speed. The rotational inertia of the ball also plays a role, but it is not the main factor in the ball's acceleration.

A Ball Gains Speed While Rolling Down a Hill Due