Question

A glass container ( k=1.05 W/m-K) with a surface area 0.3m² is filled with hot water at 100^oC and was let to cool in a room with a temperature of 27^oC. If the walls of the container are 0.8cm thick, how much heat is transferred from inside the glass to the room per second?

Answer 1

Given:

$k=1.05\:\rm W/m\cdot K$

$A=0.3\:\rm m^2$

t_1=100\:^\circ\rm C

t_2=27\:^\circ\rm C

$\Delta h=0.008\:\rm m$

The Fourier law of heat conductivity says

$$\frac{dQ}{dt}=k\frac{\Delta t}{\Delta h}A$$

$$\frac{dQ}{dt}=1.05*\frac{100-27}{0.008}*0.3=2874\:\rm W$$