The physicists are known to be daredevils. One of them, a ph…

The physicists are known to be daredevils. One of them, a physics professor’s gravitational potential energy is 1400 J as she sits 2 m above the ground in a sky diving airplane before it takes off.  What is the same professor’s gravitational potential energy when she begins to jump from the airplane at an altitude of 955 m? 

A 0.085-kg ball moving to the right with a speed of 15 m/s i…

A 0.085-kg ball moving to the right with a speed of 15 m/s is struck by a racket, causing it to move to the left with a speed of 15 m/s.  If the ball remains in contact with the racquet for 0.025 s, what is the magnitude of the average force exerted on the ball?

The physicists are known to be daredevils. One of them, a ph…

The physicists are known to be daredevils. One of them, a physics professor’s gravitational potential energy is 1300 J as she sits 2 m above the ground in a sky diving airplane before it takes off.  What is the same professor’s gravitational potential energy when she begins to jump from the airplane at an altitude of 915 m?