Chapter 2, Problem 8TE

Consider a ball at rest in the middle of a toy wagon. When the wagon is pulled forward, the ball rolls to the back of the wagon. Interpret this observation in terms of Newton's first law.

To determine

The interpretation of the reason behind the ball rolls to the back of the wagon when it is pulled forward.

Answer to Problem 8TE

When the wagon push forward, the ball tries to be in rest, but the ball rolls backward due to Newton's first law.

Explanation of Solution

Newton's first law is also known as the law of inertia, and it states that the moving body tends to remain in moving condition until an external means act over it. Also, if a body is stable, it remains in a stable position until an external means acts on it.

In case of a ball and wagon system, the force is applied to the wagon that causes a ball to rolls back of the wagon. Hence by Newton's first law, the ball stays at rest relative to the ground, so the ball tries to be in rest, but the ball rolls backward. So, the state of the ball relative to the ground is not changed according to Newton's first law.

Conclusion:

Therefore, when the wagon push forward, the ball tries to be in rest, but the ball rolls backward due to Newton's first law.