Atest charge is placed at a distance of 2.5 × 10-2 meters from a charge of 6.4 × 10-5 coulombs. what is the electric field at the test charge? (k = 9.0 × 109 newton·meter2/coulomb2)

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)