A 1.5x103 kg car is constructed on a frame supported by four springs. Each spring has a spring constant of 2.5x104 N/m. If two people riding in the car have a combined mass of 1.6x102 kg, find the frequency of vibration of each spring when a car is driven over a pothole in the road and also find the period. Assume the weight is evenly distributed.

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).