Posted by Y0gi on .
60) A class of 10 students taking an exam has a power output per student of about 200W. Assume the initial temperature of the room is 20 C and that its dimensions are 6.0 m by 15.0 m by 3.0 m. What is the temperature of the room at the end of 1.0 h if all the energy remains in the air in the room and none is added by an outside source? The specific heat is 837 J/kg C, and its density is about 1.3 x 10^-3 g/cm^3
I just need the work shown
The answer is 44.5 C (= 112 F)
The heat generated by the students at the end of one hour is
10*(200 J/s)*3600 s = ___ Joules
Divide that by the heat capacity of the air in the room,
(Volume)*(air density)*Specific heat)
The ratio will be the temperature rise.
The high value is the result of erroneous assumptions. In a real case, most of the added heat would be lost to the walls and objects in the room.
You do the calculations
I did as you said. The only thing I did not see you add to the equation though is the initial temperature of the room. I don't know if I did it right because after your instructions I just added that 20 C to the final answer and it gave me 44.5! I don't know if it's right but it gave me the correct answer.