Question

Two balls of the same size but of different materials, rubber and iron are kept on the smooth floor of a moving train. 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? Give reasons for your answer.

Answer 1

1. Yes, the balls begin to roll in the direction of the train's motion.
2. An object's inertia is a measure of its resistance to a change in its state of motion. It is solely determined by the object's mass, with larger objects having greater inertia and a greater tendency to resist changes in motion.
3. When the brakes are applied, the train comes to a stop, and the balls try to come to a stop as well.
4. However, due to inertia, the balls remain in motion and begin to roll.
5. Since the masses of the two balls differ, the inertia of the iron ball is greater than that of the rubber ball due to the large mass of the iron ball as compared to the rubber ball.
6. As a result, the rubber ball moves faster than the iron ball.