Engineering, 16.11.2019 05:31, hlgerardip4wbhx

Aroom with dimensions of 4m-by-5m-6m is to be heated by an electrical resistance heater placed in a short duct in the room. initially, the room is at 15oc and the local atmospheric pressure is 98 kpa. the room is losing heat steadily to the outside at a rate of 150 kj/min. a 200-w fan circulates the air steadily through the duct at a rate of 40 kg/min. it can be assumed that the duct operates adiabatically and there is no air leaking out or into the room. it takes 20 minutes for the average room temperature to reach 25oc. determine (a) the power supplied to the resistance heater and (b) the change in temperature of the air between the entrance and exit of the duct. (ans: (a) 3.15 kw; (b) 5 ? oc)

Answers: 3

Show answers

Other questions on the subject: Engineering

Engineering, 03.07.2019 15:10, margaret1758

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Answers: 1

continue

Engineering, 03.07.2019 15:10, EmilySerna

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

Answers: 1

continue

Engineering, 04.07.2019 18:10, QueenLife4869

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.

Answers: 3

continue

Engineering, 04.07.2019 18:20, safiyabrowne7594

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?

Answers: 3

continue

Do you know the correct answer?

Aroom with dimensions of 4m-by-5m-6m is to be heated by an electrical resistance heater placed in a...