Question

A box with inside area of 1.1m2 is covered with an unknown 0.163m of insulation material. Determine the thermal conductivity for the insulating material if a 62 W bulb is used to heat the box. The bulb maintains the inside temperature at 23oC higher than the outside temperature.

Answer 1

9514 1404 393

Answer:

0.40 W/(m·K)

Explanation:

Units of thermal conductivity are ...

W/(m·K)

The length dimension in the denominator comes from the ratio of area to thickness. That is, we can compute the thermal conductivity from ...

(62 W)(0.163m)/(1.1 m²·23K) ≈ 0.40 W/(m·K)