Question

A circular disc of mass 2 kg and radius 10 cm rolls n without slipping with a speed 2 m/s . what will be the total kinetic energy of the disc

Answer 1

Given, mass of circular disc (m) = 2, radius (r) = 10, and velocity (v) = 2m/s and total kinetic energy of the disc =?

To find I = mr2/2 => 2*(0.1)2/2 = 0.01kg – m2; w = v/r => 2/0.2 = 20radius/second.

Kinetic energy (KE) = mv2/2 + Iw2/2 => 2*4/2 + 0.01*(20)2/2 = 4 + 2 = 6J.