Question:
Two balls of the same size but of different materials, rubber and iron are kept on the smooth surface of a moving trains. The brakes are applied suddenly to stop the train. Will the balls start rolling ? If so, in which direction? Will they move with the same speed? Justify your answer. (CBSE Sample Paper)
Solution:
When train slows down, balls remain in motion due to inertia of motion. Hence, balls start rolling in the forward direction. Since mass of both the balls are different, so they move with different speed.