A 10-kg toy truck moves at 5 m/s East. It collides head-on with a 5-kg toy car moving at 10 m/s, West. What is the total momentum of the
system?

0 kg m/s
50 kg m/s
30 kg m/s
10 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).