Question

A boy, standing at point O, is whirling a ball on a string over his head. After several whirls, he lets go of the string and the ball travels in a straight line. Describe the velocity of the ball in both situations: whirling overhead and being let go.

Answer 1

D)While whirling overhead, the velocity changes. Moving in a straight line, the velocity does not change.

Answer 2

While the ball is whirling overhead it is moving in a circle. It has circular velocity. More often used term is angular velocity. This comes from the fact that ball travels some angle during some time.

When it is let go ball travels in a straight line. It has linear velocity. Word "linear" means "straight".