posted by Isabell .
A cup of coffee (with lid) is enclosed in an insulated cup 0.5 cm thick in the shape of a cube 9.7 cm on a side. The thermal conductivity of the cup is 0.0002 cal/s x cm x C. The temperature of the coffee is 71 degrees Celsius and the temperature of the surroundings is 25 degrees Celsius. Find the heat loss due to conduction in J/s.
I did it like this:
[0.0002 (6x9.7^2)(71-25)]/0.5 = 10.388
but it was wrong.