You went to move a 41 kg bookcase to a different place in the living room. if you push with a force of 65 n and the bookcase accelerates at 0.12 m/s2 what is the coefficient of kinetic friction between the bookcase and the carpet?

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.