A 0.311 kg tennis racket moving
30.3 m/s east makes an elastic
collision with a 0.0570 kg ball
moving 19.2 m/s east. Find the
velocity of the tennis racket after
the collision.

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a. true or b. false

The junction rule describes the conservation of which quantity? note that this rule applies only to circuits that are in a steady state.

Conventional hot-water heaters consist of a tank of water maintained at a fixed temperature. the hot water is to be used when needed. the drawback is that energy is wasted because the tank loses heat when it is not in use, and you can run out of hot water if you use too much. some utility companies are encouraging the use of on-demand water heaters (also known as flash heaters), which consist of heating units to heat the water as you use it. no water tank is involved, so no heat is wasted. a typical household shower flow rate is 2.50 gal/min (9.46 l/min ) with the tap water being heated from 51.0 ˚f (10.6 ˚c) to 120 ˚f (48.9 ˚c) by the on-demand heater. what rate of heat input (either electrical of from gas) is required to operate such a unit, assuming that all the heat goes into the water?