Why did physicists expect a hot filament to give off ultraviolet light as its temperature increased? a. they thought that light existed as particles of various energies. b. they thought that light could be absorbed or emitted only in specific-sized chunks. c. they thought that matter could emit only certain frequencies of light. d. they thought that as the energy increased, the frequency of light would increase.

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)