: You have a refrigeration system that takes in 397 kW of heat and puts out 599 kW of heat. What is the coefficient of performance (C.O.P.) of the system (do NOT express this value as a percentage)? View
: What is the efficiency of the heat engine in the previous problem (express your answer as a percentage)? View
: If you run a heat engine that takes in 413 kW of heat and rejects 164 kW of heat, what is the power generated by the engine? View
: Now that you’ve filled the ball, you know that it’s at a gauge pressure of 7 psi and the air inside is again at the ambient temperature of 298 K (so you filled it quickly and allowed it to reach equilibrium, as discussed in lecture). What is the new mass of air inside the ball? (Please use the absolute pressure in the ideal gas formula) View
: You need to fill up a basketball that’s low on air pressure. It’s initially at a gauge pressure of 6 psi, and you want to inflate it to 7 psi so that it is properly inflated. The volume of the ball is 7000 cubic centimeters, and you can assume that the volume of the ball remains constant as you pump air into it. What is the initial mass of air in the ball, if you assume that the air in the ball is at the ambient temperature of 298 K and that the ideal gas relations hold true for the air in the ball? (Please use the absolute pressure in the ideal gas formula) View
: *ANSWERS A LITTLE OFF. You have air flowing through a 0.5 m x 1.0 m vent. The air flows into the vent at a temperature of 300 K and a speed of 1.0 m/s. If the air leaves the vent at a temperature of 250 K, what is the rate of heat transfer that occurs in the vent? Assume that the ideal gas equation holds true for the air in this situation, and the pressure of the air is constant at 1 atm, and that this occurs over a short period of time. View
: If you have air at a temperature of 418 K and a pressure of 3 atm, what is its density if you assume that the ideal gas equation holds true? View
: Calculate the thermal efficiency of a Carnot cycle heat engine operating between reservoirs at 325°C and 35°C. View
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