How much does the temperature of an auditorium increase when filled with people?

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Homework Help Overview

The discussion revolves around calculating the increase in temperature of an auditorium when filled with people. The original poster provides specific details about the auditorium's volume, the number of people, their heat output, and relevant physical constants.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply the equation Q = mc (delta T) to determine the temperature increase, but expresses uncertainty about their calculations. Some participants question the units and values used, suggesting corrections and clarifications regarding the specific heat capacity and the density of air.

Discussion Status

Participants are actively engaging in clarifying the problem setup and ensuring that the units are consistent. There is a focus on correcting the original poster's assumptions and values, but no consensus or resolution has been reached yet.

Contextual Notes

There are indications of potential confusion regarding the units of measurement and the density of air, which may affect the calculations. The original poster's initial assumptions about the values used are being scrutinized.

Xandu
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I've been trying to solve this for about a week and I'm not sure where I'm going wrong.

The problem is to figure out how much the temperature of the auditorium increases when its full of people.

The room is 4350 cubic meters.
The meeting lasts 30 minutes (1800 seconds)
The specific heat capacity of air is 1.005 J/gram, or 1005 kJ/Kg
The mass of air is 1.2 kg/m
There are 823 people.
Each person gives off about 100 watts per second.

I've been using the equation Q = mc (delta T)

To get Q, I do 823 * 100 * 1800, which is 148,140,000

So then I do 148,140,000 / 1.2kg/m (1005kJ/Kg) ( 4350), which is 148,140,000 / 5,246,100 = 28.238 degrees Celsius, which is way off. them.
 
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Quick note: watts is a measurement of energy per time so I think you mean each person gives off 100 watts (100 joules per second). Also I think you mean the density of air is 1.2 kg/m3

Make sure you are using all standard units. (Notice that the specific heat is given as kiloJoules per kilogram.
 
Last edited:
Yes, i meant 100 joules per second, my mistake, I'll try it again with 1.3 kg/m3. Thanks
 
No sorry that was a typo on my part. If it's given as 1.2 then use 1.2.

My main point was to make sure your values are in joules.
 
Oh, that makes sense, thanks.
 

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