Question

two spheres of the same size but of the different materials rubber and iron are kept on the smooth floor of a moving Train.The Driver suddenly applies brakes and train stops will the spheres? if so in which direction and will they move with the same speed? give the give reasons for your answer..

Answer 1

The balls will start rolling because of inertial of motion. The balls were initially moving with the train, when brakes are applied the train slows down but the balls will experience a pseudo force (arising due to accelerating frame of reference of the train) and hence move in the forward direction.

The balls are of same size but are made of different material; so their masses will be different. Hence, the moment of inertia will be different. Which implies the acceleration of the balls will be different, hence, both the balls have different speed.