1) Calculate the ideal efficiency of a heat engine that takes in energy at 800 K and expels heat to a reservoir at 300K ?

What happens in a global convection cell

Convection currents are caused by differences in what two things?

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).