A400-lb object is released from rest 500-ft above the ground and falls under the influence of gravity. assume the force in pounds due to air resistance is  where  is the velocity of the object in ft/sec, determine the equation of motion of the object. when will the object hit the ground and what is its velocity at the impact

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)