Two grocery carts collide head-on, a full one with a mass of 35 kg moving east at 2 m/s and an empty one with a mass of 10 kg moving west at 3 m/s. After the collision, the full cart is moving east at 0.75 m/s. What is the velocity of the empty cart?

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).