Which of the following statements is true? Thermal pollution is the main disadvantage of hydroelectric power.
The total amount of water in an ecosystem is always increasing.
Wood and water are nonrenewable natural resources.
The greenhouse effect is primarily caused by cars and trucks.

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).