an ideal gas is enclosed in a cylinder with a movable piston on top of it. the piston has a mass of 8,000 g and an area of 5.00 cm^2 and is free to slide up and down, keeping the pressure of the gas constant. How much work is done on the gas as the temperature of .200 mol of the gas is raised from 20 degrees Celcius to 300 degrees Celcius