PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A horizontal, uniform turntable is modeled as a solid disk of radius 0.25m and mass 1.8kg. Starting from rest, the turntable must reach a rotational speed of 45revmin−1 in 2.0s. A motor drives a belt that wraps around the rim of the turntable and exerts a constant tangential force on the edge. Frictional effects are negligible during the spin-up interval.
(a) Determine the magnitude of the angular acceleration the turntable must undergo.
(b) Calculate the net torque that must act on the turntable during the spin-up.
(c) Determine the magnitude of the tangential force that the belt must exert on the rim to produce this torque.
(d) Suppose the belt instead makes contact at a point halfway between the center and the rim. Qualitatively state and briefly justify whether the force found in part (c) would increase, decrease, or stay the same.