In tennis, one of the primary ways to win a point is by making the ball bounce twice on your opponent's side of
the court. A tennis player hits a ball at a velocity of 50
m/s at a 0 degree angle from 1m high. When the ball
bounces it reflects its velocity angle perfectly and loses
30% of its speed.

How long does the other player have to return the ball
before the second bounce?

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.