Problem # p031

Conservation of energy, closed system

A fixed amount of gas inside a cylinder with a movable piston undergoes a constant-pressure process from state 1 to a state 2.
Given are :

State 1 : p1 = 1.5 bars     V1 = 0.5 m3
State 2 : V2 = 0.15 m3
Change in internal energy : U2 - U1 = 15 kJ

Neglect changes in kinetic and potential energy. Calculate the amount of heat transferred into/out of the gas during this process.