What can we say about the rock as it falls to earth? a) it accelerates as it falls. b) it falls at a constant rate of speed. c) it is at a constant velocity as it falls. d) it accelerates until it reaches a peak velocity, then decelerates.

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).