Question

After a medicine ball (3 kg) falls off a rolling wagon, what happens to the speed of the wagon?

a. The wagon slows down.
b. The speed of the wagon does not change.
c. The wagon speeds up.
d. Additional information about the ball's motion is needed to answer.

Answer 1

When a 3 kg medicine ball falls off a rolling wagon, the speed of the wagon does not change.

Step-by-step explanation:

When a 3 kg medicine ball falls off a rolling wagon, the speed of the wagon does not change (b).

The reason for this is that the medicine ball falling off the wagon does not exert a horizontal force on the wagon. According to Newton's third law of motion, the force of the ball falling off the wagon is equal and opposite to the force of the wagon on the ball. This means that the horizontal forces cancel out and there is no net force acting on the wagon, hence its speed remains the same.

For example, if you push a book on a table, the book exerts an equal and opposite force on you, but it does not affect your motion. The same principle applies here with the medicine ball and the wagon.