A household refrigerator that has a power input of 500 watts and a COP of 2 is to cool eight large watermelons, 5 kg each, to 10°C. If the watermelons are initially at 20°C, determine how long will take for the refrigerator cool them. The watermelons can be treated as water whose specific heat is 4.2 KJ/kg-K.

A household refrigerator that has a power input of 500 watts and a COP of 2 is to cool eight large watermelons, 5 kg each, to 10°C. If the watermelons are initially at 20°C, determine how long will take for the refrigerator cool them. The watermelons can be treated as water whose specific heat is 4.2 KJ/kg-K.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

A solar energy based heat engine which recieves 90kJ of heat at 900C and rejects 70kJ of heat to the ambient at 200C is to be designed. Determine the thermal efficiency of the heat engine.
The power required to drive the compressor in a Carnot refrigerator is 62 hp. It operates between -6°C and 45°C. Determine the coefficient of performance. Final answer must be in 3 decimal places.
A household refrigerator that has a power input of 450 W and a COP of 1.55 is to cool five large watermelons, 10 kg each, to 8°C. If the watermelons are initially at 28°C, determine how long it will take for the refrigerator to cool them. The watermelons can be treated as water whose specific heat is 4.2 kJ/kg-°C. Is your answer realistic or optimistic? The time taken for the refrigerator to cool the watermelons is [6222.22] min and the answer is optimistic Drev 3 of 9 # Next Next >
A room measures 4mx7mx5m and the air in it has to be always kept 20 C0 lower than that of the incoming air. The air inside has to be renewed every 30 minutes. Assuming 75% efficiency, calculate the HP rating of an air-conditioning unit suitable for this purpose. Take specific heat of air as 0.24 and its density as 1.27 kg/m^3.
A refrigerator that has a power (electric) input of 450W and a COP of 2.5 is to cool five large watermelons,10 kg each, to 8°C. If the watermelons are initially at 20°C, determine how long it will take for therefrigerator to cool them. The watermelons can be treated as water whose specific heat is 4.2 kJ/kgK.
Determine the COP of a refrigerator that removes heat from the food compartment at a rate of 5250 kJ/h for each 1.25 kW of power it consumes. Also, determine the rate of heat rejection to the outside air.
An ideal Carnot heat pump operates from a low temperature reservoir T₁-281.2 K and supplies 5.91 kW of high temperature heating power to a house with high temperature Th=311K. Determine the power that a motor needs to drive the pump. Present your answer in kilo-Watts (kW).
Please give the detailed solution. Mechanical -thermo
A refrigerator is removing .25 heat from a cold medium at 3°C at a rate of 7200 kJ/h and rejecting the waste heat to a medium at 30°C. If the coefficient of performance of the refrigerator is 2, the power consumed by the refrigerator is
When a man returns to his well-sealed house on a summer day, he finds that the house is at 35°C. He turns on the air conditioner, which cools the entire house to 20°C in 36 min. If the COP of the air-conditioning system is 2.8, determine the power drawn by the air conditioner. Assume the entire mass within the house is equivalent to 800 kg of air for which cy= 0.72 kJ/kg °C and cp = 1.0 kJ/kg-°C. 35°C 20°C W A/C The power drawn by the air conditioner is kW.
A steam power plant has a high pressure of 2.5 MPa after release from the pump and it maintains 40°C in the condenser. The quality of the stream exiting the turbine is 80%. Solve for the work produced by the turbine and the pump, the heat transfer in the boiler, and heat removed by the condenser. (Answer in kJ/kg)