Calculate the power temperature

AI Thread Summary
The discussion revolves around calculating the power generated by humans from a typical daily diet of 2000 kcal and its effect on room temperature for 250 people in a 15,000 m³ space over an hour. The initial calculation yielded a power output of 2.3 W, which was later corrected, noting that the time should reflect a full day rather than an hour, significantly increasing the power value. The specific heat capacity of air is also mentioned, but the user struggles with applying the relevant equations to find the temperature increase. Clarifications on the definitions of power and energy units are provided, emphasizing the need for accurate calculations. The conversation highlights the importance of understanding the relationship between energy, power, and temperature changes in a given volume.
JQ10
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Edit: Topic title should read power and temperature

Homework Statement



Humans convert most of a 2000 kcal typical daily diet into heat. Calculate the power. What is the increase of temperature in a room with a volume of 15000 m^3 filled with 250 people over a 60 minute period?

Note: Power is defined as energy/time.
1kcal = 4.186kJ.
density of air = 1.29kg/m^3
molar mass of air = 29g
Treat air as a diatomic gas


Homework Equations



C = change in internal energy/ number of moles * change in temperature = f/2*R



The Attempt at a Solution



60 * 60 = 3600

2000 * 4.186 = 8372kJ/3600s = 2.3kJ/s = 2.3W

Specific Heat Capacity = 5/2 * R = 5/2 * 8.31 = 20.8 kJ/moleK

I'm really struggling with where to take it from there. I'd guess you would either use change in internal energy/ number of moles * change in temperature or use average kinetic energy = 5/2kT = 1/2mv^2rms but I'm not sure how to calculate the relevant data for either plus that doesn't use all the information given.
 
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JQ10 said:
Humans convert most of a 2000 kcal typical daily diet into heat.
60 * 60 = 3600
2000 * 4.186 = 8372kJ/3600s = 2.3kJ/s = 2.3W

I have not played with attempting the find the specific heat of air before so I'll let someone else help you there. I can tell you that the power involved is not 2.3 W because there are not 3600 seconds in a day. Note that the problem said "daily." And a watt is not equal to kJ/s but J/s. Due to those two errors, your power is small by an order of magnitude.
 
Thank you for the help.
 
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