Despite a very strong wind, a tennis player manages to hit a tennis ball with her racquet so that the ball passes over the net and lands in her opponent’s court. Consider the following forces: 1. A downward force of gravity, 2. A force by the hit, and 3. A force exerted by the air. Which of the above forces is (are) acting on the tennis ball after it has left contact with the racquet and before it touches the ground?
a. 1. 1 and 2.
b. 2. 2 and 3.
c. 3. 1 only. 4.
d. 1, 2, and 3.
e. 5. 1 and 3.

After the ball has left contact with the rocket, there is no more interaction between the ball and the racket, therefore the force exerted by the hit is no longer acting on the ball.

This means that there will be only 2 forces acting on the ball while it is in motion:

- The downward force of gravity: this force always acts on every object near the Earth's surface, so in this case is also acting on the ball in motion

- The air resistance: this force is due to the friction between the molecules of air and the molecules of the surface of the ball, and it acts in the opposite direction to the motion of the ball, making it slowing down

Therefore, the correct option is

e. Only 1 and 3

where

1. A downward force of gravity

3. A force exerted by the air