A 36-m room is to be heated by three ton(1 ton =1000 kg) of liquid water contained in a tank that is placed in the room. The room is losing heat to the outside at an average rate of 6700 kJ/h. The room is initially at 20 °C and 100 kPa and is maintained at an average temperature of 20 °C at all times. If the hot water is to meet the heating requirements of this room for a 24-h period, determine the minimum temperature of the water when it is first brought into the room in °C. Assume constant specific heats for both air and water at room temperature. Use Cpwater = 4180 J/kg.K and Cpair=1.005 J/kg.K %3D O 54.4 O 36.1 O 41.8 O 38.7 32.8

A 36-m room is to be heated by three ton(1 ton =1000 kg) of liquid water contained in a tank that is placed in the room. The room is losing heat to the outside at an average rate of 6700 kJ/h. The room is initially at 20 °C and 100 kPa and is maintained at an average temperature of 20 °C at all times. If the hot water is to meet the heating requirements of this room for a 24-h period, determine the minimum temperature of the water when it is first brought into the room in °C. Assume constant specific heats for both air and water at room temperature. Use Cpwater = 4180 J/kg.K and Cpair=1.005 J/kg.K %3D O 54.4 O 36.1 O 41.8 O 38.7 32.8

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

Water enclosed in a rigid tank is heated from 120°C to 250°C. The pressure is high enough that the water remains subcooled (compressed) liquid during the process. Determine the thermal energy needed for the process (in kJ) if the mass of water is 8 kg. You can use water property tables or the incompressible substance assumption.
A piston-cylinder device contains 9.4 kg of refrigerant R-134a at 100 kPa and has a volume of 1.8 m3. The refrigerant is now heated at constant pressure until the temperature becomes 60 oC. Determine: (a) The initial temperature of the refrigerant (oC), (b) The final volume of the refrigerant ( in m3), (c) The amount of work done during the process (in kJ), (d) The change in the internal energy of the refrigerant (in kJ). Submit your solution by multiplying (a)*(b)*(c)*(d)/100000 = Format answer : -87.8 Submit
8.2 kg of saturated water vapor at 200 kPa in a rigid container exchanges heat to the surroundings until its temperature reaches 110°C. What is the heat exchanged in this process (in MJ)?
A 10-cm diameter copper ball is to be heated from 90°C to an average temperature of 150°C in 30 minutes. Taking the average density and specific heat of copper in this temperature range to be 8950 kg/m3 and Cp = 0.395 kJ/kg · °C, respectively, determine the average rate of heat transferred to the ball.
Nitrogen in a rigid vessel is cooled by rejecting 100 kJ/kg of heat. Determine the internal energy change of the nitrogen in kJ/kg.
Consider two identical rooms, one with a 2-kW electric resistance heater and the other with three couples fast dancing. In which room will the air temperature rise more quickly?
A 0.3m³ rigid tank initially contains saturated liquid water at 200°C. A valve at the bottom of the tank is opened until half of the mass in saturated liquid form is withdrawn from the tank. The temperature is maintained constant. Determine the amount of heat transfer during this process. Sat. liquid T = 200°C V = 0.3 m³
A piston cylinder containing steam at 700 kPa and 250 degree Celsius undergoes constant pressure process until its quality is 70%. Determine the work done in kJ/kg and heat in kJ/kg.
A gas contained in a vertical cylindrical tank has a volume of 11.12 m3. The gas receives a paddle work of 7.5W for 1hour. If the density of the gas at the initial state is 1.5 kg/m3, determine the specific heat gain or loss if the specific internal energy of the gas increases by 16.2kJ/kg.
An insulated piston-cylinder device initially contains 1.8 kg of Argon at 100 kPa and 300 K. Now an electric resistor placed in the tank is turned on for 6 minutes until the (Volume2 = 2.3*Volume1).What is the power rating of the electric heater (W)?
A piston-cylinder device contains 50 kg of water at 250 kPa and 25°C. The cross-sectional area of the plunger is 0.1 m2. Heat is transferred to the water, causing some of it to evaporate and expand; When the volume reaches 0.2 m3, the piston hits a linear spring whose spring constant is 100 kN/m. More heat is transferred to the water until the plunger rises a further 20 cm. Determine a) the final pressure and temperature and b) the work done during this process. Also show the process on a P-V diagram.