Two balls of the same size but different matetials, rubber and iron are kept on the smooth floor of a moving train. The brakers are applied suddenly to stop the train . Will the balls start rolling? If so, in which direction? Will they move with the same speed? Give reasons for your answers.

Explanation

Yes, both the balls will start rolling due to inertia of motion. The train stops due to brakes. But the balls continue to move in the direction of the train. The two balls will not roll with the same speed. Infact, the iron ball being heavier than the rubber ball shall move at a lower speed.