An ideal gas in a cylinder occupies a volume of 0.065 m3 at room temperature (t = 293 k). the gas is confined by a piston with a weight of 100 n and an area of 0.65 m2. the pressure above the piston is equal to one atmosphere (atm = 1.013x105 pa). the piston is free to move up and down. 1) what is the magnitude of the net force on the piston? zero 50 n 100 n 2) briefly explain your answer.

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.