Question

A class XI student tied a ball to the end of a string and made it move in a horizontal plane about a fixed point with a constant angular speed. She observed that the ball then performed a uniform circular motion in the horizontal plane. Now, she observed the ball sideways fixing her attention in the plane of motion. The ball appeared to execute to and fro motion along a horizontal line with the point of rotation as the midpoint. She then made the following figure to explain the situation graphically.