A passenger in a moving bus with no windows notices that a ball that has been at rest in the aisle suddenly starts to move to-ward the rear of the bus. Think of two possible explanations, and devise a way to decide which is correct.
Solution 9DQ Two possible explanations for the given situation are as follows. 1. The bus starts accelerating suddenly. In this case, due to the inertia of rest the ball tends to remains in its initial position. Hence it reaches the rear of the bus when the floor of the bus gets accelerated. 2. The bus starts moving up in an inclined plane. The bus has to do this against the gravitational force and the ball therefore will move downward the inclined plane of the bus.