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?

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)

Amother used 150 watts of power to raise a 15 newton object in a time interval of 8.0 seconds. through what vertical distance was the object raised ?