A man weighing 60 kg is standing on a trolley weighting 240 kg. The trolley is resting on frictionless horizontal rails. If the man starts walking on the trolley with a velocity of 1 m/s, then after 5s, his displacement relative to the ground is

Options

A. 5m/s
B. 4.8m
C. 3.2m
D. 3.0m

Answer

C

Explanation

Displacement of the man w.r.t. trolley in 4sec `x_(CM) + x_(T)= 4 xx 1= 4 rArr x_(T)= 4- x_(CM)`
Position of centre of mass remain constant `(4- x_(CM))320 = x_(CM) xx 80 rArr x_(CM)= (16)/(5)= 3.2m`