An isolated turntable rotates at a constant angular velocity of
PHYSICS · Single correct · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
An isolated turntable rotates at a constant angular velocity of 8.0rad/s. Which statement best describes the net external torque acting on the turntable?
(a) A constant non-zero external torque must act in the direction of rotation to keep the disk spinning at 8.0rad/s.
(b) A constant external torque acts opposite the direction of rotation to cancel out frictional forces.
(c) The net external torque is zero; therefore the turntable's angular velocity remains constant.
(d) The external torque continuously changes direction during each revolution, so its average value over time is zero.