Question

A ball is attached to a string and whirled in a horizontal circle such that it moves with constant speed. Which of the following statement is correct? The velocity is changing but the acceleration is equal to zero. The velocity is changing and the acceleration is not equal to zero. The velocity is constant but the acceleration is equal to zero. The velocity is constant but the acceleration is not equal to zero.

Answer 1

The velocity is changing and the acceleration is not zero.

Velocity is a vector quantity and although the speed is constant the velocity is not because the ball is constantly changing direction .

acceleration = v^2 / R acceleration is constant and is directed towards the center of the circle