Why is it important to use substitute energy?

PLEASE HELP! The rate of energy use in a typical house is about 2 kW. If the kinetic energy of a car?

• 1) The rate of energy use in a typical house is about 2 kW. If the kinetic energy of a car (mass 1526 kg) is equal to the total energy used by the house in 1 min, what is the car's speed? _______m/s 2) A tennis ball (m = 55 g) is projected vertically with an initial speed of 9.1 m/s. (a) If the ball rises to a maximum height of 3.5 m, how much kinetic energy was dissipated by the drag force of air resistance? _______J (b) How much higher would the ball have gone in a vacuum? _______m 3)An electric motor is rated to have a maximum power output of 0.76 hp. If this motor is being used to lift a crate of mass 196 kg, how fast (i.e., at what speed) can it lift the crate? Hint: Assume the only other force on the crate is the force of gravity. _______m/s

• Answer:

  1) P = 2 kW, t = 1 mins 2 kW-min = 120,000 J KE = (1/2) mv^2 KE = 120,000 = (1/2) * (1526) * v^2 v =12.54 m/s 2) TBC .