A loop of radius 2 m weights 100 kg. It rolls along a horizontal floor so that its centre of mass has a speed of 20 cm/*. How much work is done to stop it?
R = 2 m, M = 100 kg
v = 20 cm/ = 0.2 m/
Total energy of the loop
Work required to stop the hoop = total energy of the hoop
= 100 (0.2)2 = 4
