Heat Capacity and Energy supplied

1. Jan 21, 2007

nina

I'm stuck on some basic physics...

I'm using the formula E=mc (delta T/delta t) where E is energy, m is mass, c is specific heat, T is temperature and t is time, to calculate the energy used in heating a volume of air to a certain temperature.

Assuming that pressure is of that at sea level, I come up with a rate of heating of 12.56J per second, for a 16K rise in temperature over 10 hours, for a volume of air of 24m3.

This seems a little high, what did I do wrong?

2. Jan 21, 2007

joshd

???

we have just been told that E=mc*deltaT, in both physics and chemsitry...?

where did you get the (deltaT/deltat) ?

EDIT: ah ha! i see where the discrepancy lies... you are working out energy per second. sorry.

3. Jan 21, 2007

Gokul43201

Staff Emeritus
That's about the same number I get...but next time:

1. Please post such questions in the Homework & Coursework subforums, and
2. Use the template provided (and write down the original question EXACTLY as it was given to you).

4. Jan 22, 2007

nina

Thanks, but it's not homework! I'm trying to work it out for myself for another project, needed to check the answer before I went forward with the work!

That IS the original question, shows why I shoudnt be a teacher!