A 20-kW electric heater is used to heat up a house with size measured 6 m x 8 m x 10 m. The house is equipped with a 500-W TV set, a 25-W light bulb, and a 250-W workstation. Heat is losing through windows at a rate of 500 kJ/min. On a cold winter day, the temperature dropped to 10°C, owner switched on the TV, workstation and heater. Determine the time needed to increase the indoor temperature to 25°C.

Q: containing air to the environment, work input to the room at a speed of 1.2 kW from computers, TVs…

A:

Q: a) A gas is trapped in a piston-cylinder device. The initial pressure and temperature of the gas are…

A:

Q: A Carnot engine operating between 775 K and 305 K produces 51.18 Btu of work. Calculate the heat…

A:

Q: For an energy storage capacity of 5 × 106 kWh, determine the minimum amount of water that needs to…

A:

Q: house is to be maintained at 20°C when the outside air is at -25°C. It is determined that 1800 kJ is…

A: Given:Ti=20 CTo=-25 CQs=1800 KJ/minR=13 cents/KWh

Q: A room is maintained at 20°C by removing heat at a rate of 3 kW. The required power input to the air…

A:

Q: A heat pump is absorbing heat from the cold outdoors and supplying heat to a house. The house is…

A:

Q: Two volumes of air are separated by a thin rectangular heater (0.2 cm x 15 cm x 2 cm). The…

A:

Q: A household freezer operates in a room at 20°C. Heat must be transferred from the cold space at a…

A: Room temperature, TH=20oC=20+273=293 KCold space temperature, TL=-20oC=-20+273=253 KHeat transferred…

Q: Calculate the increase in internal energy of a gas in a closed system during a process in which 100…

A:

Q: A house is to be maintained at 20°C when the outside air is at -25°C. It is determined that 1800 kJ…

A:

Q: A device collects energy from the sun's rays and produces a high temperature of 95 °C. A small heat…

A: Given Data TH=95°C TL=15°C=288 K

Q: A heat pump is used to maintain a space at 25 C during winter while the outdoor temperature is 10 C.…

A:

Q: gas inside a piston-cylinder arrangement is being compressed by a 50 kJ of work. If its internal…

A: Given:W=-50 KJU1=60 KJU2=100 KJ

Q: A 100W CPU with a size of 10x 10 cm is cooled at steady state with 25°C water that is pumped through…

A:

Q: A heat engine is used to pump oil out of an underground mine. If the heat engine produces 400 kJ of…

A: A heat engine operates on the principle of energy conservation. It accepts heat from a…

Q: A Carnot heat engine receives heat from a high temperature source at 655°C and rejects heat to a…

A:

Q: A heat pump uses 100 J of energy as it operates for a given time. Isit possible for the heat pump to…

A: Heat pump is thermodynamic device which fetches or extracts heat energy from a  thermal heat…

Q: Icecream container is to be keep in an existing state at 233.15 K in a hot weather where the…

A: To Find : The minimum power in watts required for this machine. Given : The lower temperature is…

Q: Determine the COP (coefficient of performance) of a heat pump if the rate of heat rejected is 360…

A: Given, Rate of heat rejection = QR = 360 kJ/min Power supplied = W = 2 kW   Rate of heat rejection…

Q: A heat pump absorbs 10 kW of heat from outside environ- ment at 250 K while absorbing 15 kW of work.…

A: Useful data from the given question is as below, Heat absorbed from low-temperature reservoir = QL =…

Q: the minimum area of the solar collector

A: Given; A solar collector recieving solar radiation at the rate of;Q=0.6 KW/m2Overall efficiency of…

Q: 6-49 An air conditioner removes heat steadily from a house at a rate of 750 kJ/min while drawing…

A: COP = 2.39rate heat transfer = 17.75 KWExplanation:a)COP = (rate of removing heat in KW) / (electric…

Q: A refrigerator has a broken light bulb inside that is constantly turned on even when the…

A: Given:Power of light bulb, P=20 WCoP of refrigerator=1.4Electricity cost=12/ kWh

Q: In a cylinder, the heat rejected is 32 kJ while the decrease in internal energy of the gas is 92 kJ.…

A:

Q: A household refrigerator with a COP of 1.25 removes heat from the refrigerated space at a rate of…

A:

Q: Find the required power (in kW) to operate this cooling machine and the lowest temperature inside…

A: Given: Environment temperature (TH)= 23oC= 296 K Q2=210 kJ/min = 3.5 kW COP=4.5 TO determine: The…

Q: 300 kJ of thermal energy is stored at a temperature of 1000 K. Assuming perfect heat transfer to a…

A:

Q: the irreversibility (in W) due to heat transfer through the

A: Given. One side of a wall is maintained at,T1=400 KT2=300 KHeat transfer rate,Q=…

Q: In a fossil fuel power plant the chemical energy stored in fossil fuels such as coal, fuel oil,…

A: GIVEN; Coal-fired plant with a capacity of 100 MW = 100×106 W 60% efficiency (40% is lost as heat)…

Q: A refrigerator operating between -5°C and 27°C has the capacity of 80 tons. Determine the number of…

A: Write the given data in the problem.  m=10 kgT1=27°CT2=0°C Here, m is the mass of the refrigerator,…

Q: One side of a wall is maintained at 400 K and the other at 300 K. The rate of heat transfer through…

A: Given Ts1=400 KTs2=300 KQ.=1000 WTsur=25oC To find Rate of heat transfer within wall