A225 kg red bumper car is moving at 3.0 m/s. it hits a stationary 180 kg blue bumper car. the red and blue bumper cars combine and hit a stationary green bumper car of mass 150 kg. the red, blue, and green bumper cars all combine. what is the final velocity of the combined bumper cars?

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).