What branch of physics best explains the photoelectric effect?
a.) nature of light
b.) general relativity
c.) law of conservation of momentum
d.) thermodynamics

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

What is the kinetic energy of a baseball moving at a speed of 40 m/s if the baseball has mass of 0.15 kg?

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.