A piston compresses the air in the cylinder by doing 41.0 J of work on the air. As a result, the air gives off 121.0 J of heat to the surroundings. If the system is the air in the cylinder, what is the change in its internal energy

Refrigerant-134a flows through a carnot heat pump cycle at 0.5 kg/s. it is known that the maximum absolute temperature in the cycle is 1.1 times the minimum absolute temperature, and the net power input to the cycle is 2.5 kw. if the refrigerant changes from a saturated vapor to a saturated liquid during the heat rejection process, determine the maximum magnitude of the enthalpy of vaporization for this process in kj/kg (with 3 significant figures).