subject
Engineering, 25.09.2019 01:20 pookie1971

If an aluminum plate 4 mm thick is mounted in a horizontal position, and its bottom surface is well insulated. a special, thin coating is applied to the top surface such that it absorbs 80% of any incident solar radiation, while having an emissivity of 0.25. the density p and specific heat c of aluminum are known to be 2700 kg/m3 and 900 j/kg k, respectively. (a) consider conditions for which the plate is at a temperature of 25 c and its top surface is suddenly exposed to ambient air at t=20 c and to solar radiation that provides an incident flux of 900 w/m2 . the convection heat transfer coefficient between the surface and the air is h = 20 w/m^2 k. what is the initial rate of change of the plate temperature?

ansver
Answers: 3

Other questions on the subject: Engineering

image
Engineering, 04.07.2019 18:10, niicoleassssssf
Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86
Answers: 2
image
Engineering, 04.07.2019 18:10, lillygrl100
For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater
Answers: 3
image
Engineering, 04.07.2019 18:10, Strick1530
Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.
Answers: 2
image
Engineering, 04.07.2019 18:20, samantha636
Avolume of 2.65 m3 of air in a rigid, insulated container fitted with a paddle wheel is initially at 264 k, 5.6 bar. the air receives 432 kj by work from the paddle wheel. assuming the ideal gas model with cv = 0.71 kj/kg • k, determine for the air the amount of entropy produced, in kj/k
Answers: 2
You know the right answer?
If an aluminum plate 4 mm thick is mounted in a horizontal position, and its bottom surface is well...

Questions in other subjects:

Konu
Mathematics, 26.02.2020 22:47