A282 kg bumper car moving right at 3.50 m/s collides with a 155 kg bumper car moving 1.8 m/s left. afterwards, the 282 kg car moves right at 0.800 m/s. what is the momentum of the 155 kg car afterwards? (unit=kg*m/s)

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).