Two bodies X and Y of mass 5.0 kg and 7.5 kg respectively are connected by a light in extensible string if x is placed on a rough surface of coefficient of friction 0.5, calculate the magnitude of the 1 normal friction
2 frictional forces between x and the surface
3 tension on the string​

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)