Year: 2019
Topic: System of particles and rotational motion
Time :
1.
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?
(1). 1 J
(2). 3 J
(3). 30 kJ
(4). 2 J