Amotor does a total of 480 joules of work in 5.0 seconds to lift a 12-kilogram block to the top of a ramp. the average power developed by the motor is
(1)8.0 w
(2)40. w
(3)96 w
(4)2400 w

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

Ais a machine that makes work easier when a single force is applied. a simple machine b compound machine c endangered machine d complex machine

During cooling, the kinetic energy of the molecules falls. why does this happen? a.the motion of the molecules increases. b. the motion of the molecules slows down. c.the van der waals forces between molecules decrease d. the forces of attraction between the molecules are overcome.