Question

Estimate the rate at which ice melts in a wooden box 0.04m thick, of inside measurement 0.6 m × 0.4m × 0.4m. Assume that the outside temperature is 300 K and the conductivity of wood is 0.08 wm^-1K^-1.

Answer 1

Area of the box

= A = 4 × (0.6 × 0.4) + 2 × (0.4 × 0.4) = 1.28m²

d = 0.04m

k= 0.08wm^-1K^-1

L= 3.36 × 10⁵Jkg^-1

Let Q be the heat transmitted per second.

To melt 1 kg of ice, 3.36 × 10⁵J of heat is required 

∴ Rate at which ice melts

\(\frac{69.12}{3.36 \times 10{^-5}}\)

= 20.57 × 10^-5kgs^-1.