A 1800 kg car is parked at the top of a hill 4.7 m high. B. The car’s brakes fail and it rolls down the hill. At the bottom of the hill, what is the potential energy of the car?

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

The air in an automobile tire with a volume of 2.60 ft3 is at 70°f and 21 psig. determine the amount of air that must be added to raise the pressure to the recommended value of 30 psig. assume the atmospheric pressure to be 14.6 psia and the temperature and the volume to remain constant. the gas constant of air is ru = 53.34ft⋅lbflbm⋅r(1 psia144 lbf/ft2) = 0.3704 psia⋅ft3lbm⋅r the amount of air that must be added to raise the pressure is lbm

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in