One mole of an ideal gas goes through a stirling cycle where it expands isothermally at a temperature of 400 k from a volume of 1 liter to a volume of 3 liters (process 1), goes through an isochoric (constant v) process to a temperature of 300 k (process 2), is compressed back isothermally to its initial volume (process 3) and is then brought back to its initial state isochorically (process 4). 1)what is the work done by the gas wby during one complete cycle?