Chapter 8, Problem 8.63P

A 4 kW 20L water heater is switched on for 10minutes. The heat capacity of water is 4.187 kJ/kgK. Assuming total electrical energy has gone intoheating the water, find the increase in watertemperature.

/Heat is transferred from a tank of water in a refrigerator at(OC) degrees to a tank of boiling water at (100 C) degrees. With a reversible machine (heat pump). Calculate the Heat drawn from the refrigerator. if it was The heat transferred to the tank of boiling water is 2254kJ.

Suppose 400 kW of power potential is wasted during the process as a result of irreversibility. Let say the heat pump received heat at a rate of 1000 kJ/s from a heat source. The reversible power of the present process is found to be 800 kW. Find unavailable heat, which is rejected to the sink.

Find the COP of heat pump operating between 300 K and 600K temperature. If the same temperature ranges are used in heat engine, find the efficiency.

A tank of water has a shaft rotating at 60 rpm with a torque of 40 N-m that is stiring the water. A heater is also present that operates at 120V and draws 4A of current. Heat is then removed from the water such the the total energy content of hte water is constant. How much heat is removed?

Find COP of refrigerator and heat pump operating between temperatures 300 K and 900 K

In a turbine, steam enters with an enthalpy of 1275 Btu/lb, and leaves with an enthalpy of 1115 Btu/lbm. The transferred heat is 13 Btu/ibm. Find the turbine work in hp where the steam flow rate is 5 lbm/sec?

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A computer lab filled with 20 computers and 15 students is cooled by an air conditioningunit on a day where it is 90 oF outside. The room temperature is 72 oF. Assume an averagestudent generate 90 W of heat and each computer generates 150 W of heat. If the COP ofthe air conditioner is 2.5, what power input is required, in kW? If the air conditioneroperated at its maximum coefficient of performance, what power input would be required?