For flow over a flat plate, both velocity and thermal boundary layer develop along the plate. at the place where the velocity boundary layer becomes turbulent, one can expect the convection heat transfer coefficient to a) increase b) decrease c) have no significant change

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.