Question

a man weighing 80 kg is standing in a trolley weighing 320 kg at raw the trolley is resting on frictionless horizontal race if the man starts walking on the trolley with a speed of 1 metre per second then after 4 seconds his displacement relative to the ground will be ​

Answer 1

Answer:

In 1s, man has walked, 4m/s×1s=4m, with respect to the trolley.

As position of the CoM stays same, let the distance moved by trolley be x in direction opposite to that of man.

So net diplacement of man is (4−x)m

Thus, Mman×(4−x)=Mtrolleyx

⟹80(4−x)=320x⟹x=320/400=0.8m

So net displacement of man in 1s is, 4−0.8=3.2m