10:42Thermodynamics - 6-4 Refrigerators and Heat Pumps - another exampleEngineering Deciphered278views
12:30Mechanical Engineering Thermodynamics - Lec 6, pt 4 of 4: Refrigerators and Heat PumpsRon Hugo220views
15:54Anti-Heat Engines: Refrigerators, Air Conditioners, and Heat Pumps | Doc PhysicsDoc Schuster257views
Textbook QuestionA man stands on the roof of a 15.0-m-tall building and throws a rock with a speed of 30.0 m/s at an angle of 33.0° above the horizontal. Ignore air resistance. Calculate (d) Draw x-t, y-t, υx–t, and υy–t graphs for the motion.834viewsHas a video solution.
Multiple ChoiceA refrigerator has a coefficient of performance of 2.4. Each cycle, it takes in 3×104 J of heat from the cold reservoir. How much is expelled to the hot reservoir?425views1rankHas a video solution.
Multiple ChoiceFreezing a kilogram of water, initially at 20°C, requires your refrigerator to remove about 417kJ of thermal energy from the water. If the coefficient of performance of your refrigerator is 5.0, how much heat is exhausted into your kitchen when you freeze a kilogram of water?455views
Multiple ChoiceWhat is the maximum possible coefficient of performance for a refrigerator operating between 2.0°C (a typical refrigerator temperature) and 20°C (a typical kitchen temperature)?329views
Textbook QuestionA certain brand of freezer is advertised to use 730 kW•h of energy per year. (c) What is the theoretical maximum amount of ice this freezer could make in an hour, starting with water at 20.0°C?758viewsHas a video solution.
Textbook QuestionA certain brand of freezer is advertised to use 730 kW•h of energy per year. (a) Assuming the freezer operates for 5 hours each day, how much power does it require while operating?326viewsHas a video solution.
Textbook QuestionA refrigerator has a coefficient of performance of 2.25, runs on an input of 135 W of electrical power, and keeps its inside compartment at 5°C. If you put a dozen 1.0-L plastic bottles of water at 31°C into this refrigerator, how long will it take for them to be cooled down to 5°C? (Ignore any heat that leaves the plastic.)1373viewsHas a video solution.
Textbook QuestionThe coefficient of performance K = H/P is a dimensionless quantity. Its value is independent of the units used for H and P, as long as the same units, such as watts, are used for both quantities. However, it is common practice to express H in Btu/h and P in watts. When these mixed units are used, the ratio H/P is called the energy efficiency ratio (EER). If a room air conditioner has K = 3.0, what is its EER?518viewsHas a video solution.
Textbook QuestionHome air conditioners in the United States have their power specified in the truly obscure units of tons, where 1 ton is the power needed to melt 1 ton (2000 lb or 910 kg) of ice in 24 hours. A modest-size house typically has a 4.0 ton air conditioner. If a 4.0 ton air conditioner has a coefficient of performance of 2.5, a typical value, at what rate in kW is heat energy removed from the house?118viewsHas a video solution.
Textbook Question100 mL of water at 15℃ is placed in the freezer compartment of a refrigerator with a coefficient of performance of 4.0. How much heat energy is exhausted into the room as the water is changed to ice at -15℃?129viewsHas a video solution.
Textbook QuestionAn air conditioner removes 5.0 x 10⁵ J/min of heat from a house and exhausts 8.0 x 10⁵ J/min to the hot outdoors. b. What is the air conditioner's coefficient of performance?150viewsHas a video solution.
Textbook QuestionWhat are (a) the heat extracted from the cold reservoir and (b) the coefficient of performance for the refrigerator shown in FIGURE EX21.21?126viewsHas a video solution.
Textbook QuestionA freezer with a coefficient of performance 30% that of a Carnot refrigerator keeps the inside temperature at -22℃ in a 25℃ room. 3.0 L of water at 20℃ are placed in the freezer. How long does it take for the water to freeze if the freezer's compressor does work at the rate of 200 W while the water is freezing?126viewsHas a video solution.
Textbook Question(II) An ideal (Carnot) engine has an efficiency of 33%. If it were possible to run it backward as a heat pump, what would be its coefficient of performance?15viewsHas a video solution.