A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed of 20 cm/s. How much work is needed to stop it?

Correct option is A. 3J
We know, Work required = change in kinetic energy
Here, Final KE = 0
So Initial KE = 1/2mv² + 1/2Iω² = 3/4mv² = 3/4 × 100 × (20 × 10⁻²)² = 3J
△KE = 3J
Hence option A is correct answer