A puck moves on a horizontal air table. It is attached to a string that passes through a hole in the center of the table. As the puck rotates about the hole, the string is pulled downward very slowly and shortens the radius of rotation, so the puck gradually spirals in towards the center. What happens to the puck's angular speed?

Question

Quizplus · Accepted Answer

The Answer is The tension in the string is directed towards the center,so there is no torque about the center.Thus,its angular speed has to increase to keep the angular momentum constant.

A Puck Moves on a Horizontal Air Table