A tennis ball of mass 0.060 kg travels horizontally at a speed of 25m/s. The ball hits a tennis racket and rebounds horizontally at a speed of 40 m/s.

Before hitting the Racket, the ball is going towards the racket at 25 m/s.

After Hitting the Racket the ball of going away from the racket at 40 m/s.

The ball is in contact with the racket for 50 ms.
What force does the racket exert on the ball?
A 0.018N
B 0.078N
C 18N
D 78N

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?

As microwave light travels through a liquid, it moves at a speed of 2.2 x 108 m/s. if the frequency of this light wave is 1.1 x 108 hz, what is the wavelength of this microwave?