Question

A solid cylindrical disk has a radius of 0.15 m. It is mounted to an axle that is perpendicular to the circular end of the disk at its center. When a 50-N force is applied tangentially to the disk, perpendicular to the radius, the disk acquires an angular acceleration of 110 rad/s2. What is the mass of the disk?

Answer 1

Torque = I α = 1/2 M R^2 α where α is the angular acceleration

Torque = F R where F is applied to a distance R from center

F R = 1/2 M R^2 α

M = 2 F / (R α) = 2 * 50 / (.15 * 110) = 6.06 kg