1.

A monkey of mass 20kg rides on a 40kgtrolley moving with constant speed of 8m/salong a horizontal track. If the monkey jumpsvertically to grab the overhanging branch of atree, the speed of the trolley after themonkey has jumped off is(A) 8 m/s(C) 4 m/s(B) 1 m/s(D) 12 m/s

Answer»

The momentum of the cart must be the same, before and after the monkey jumps off. Mm = mass of monkey and Mt = mass of the trolley. (Mm + Mt) * V1 = Mt * V2 V2 = V1 * (Mm + Mt) / Mt V2 = 8 m/s * (20 kg + 40 kg) / 40 kg V2 = 12 m/s, so the answer is (d)

hey Rajit can u plz tell y it cannot be done with law of conservation of energy



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