A boy pulls a 50 kg crate across a level floor with a force of 200 N. If the force acts at an angle of 30 degrees up from the horizontal, and the coefficient of kinetic friction is 0.30, determine A) the normal force exerted on the crate by the floor
B) the horizontal force exerted on the crate by the floor
C) the acceleration of the crate

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)