1.)An object moves along a straight line. First it travels at a velocity of 12m/s for 5s and then continues at the same direction with 20m/s for 3s. What is its average speed? 2.)A car travels along the x-axis for 4s at an average velocity 10m/s and 2s with an average velocity 30m/s and finally 4s with an average velocity 25m/s. What is its average velocity across the whole path?

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).