Iin a flexural test of a standard 2 by 2 by 30-in. douglas-fir specimen (28-in. span), the deflection at midspan was 0.125 in. when the center load was 800 lbs., the load still being within the elastic range. the beam failed at a center load of 2,800 lbs. when the deflection was 0.600 in. compute the modulus of elasticity.

In the winter, in order to keep the classroom steadily at 68 f before 10 pm, heating with an average rate of 42,000 btu/hr is provided. assume the outdoor temperature maintains at 32°f, determine the electrical power (kw) required to (a) operate a reversible heat pump (b) operate a real heat pump with a cop (7) of 4.5 and (c) operate an electrical-resistance heater.