Chapter 4, Problem 98P

A thick wood slab $(k=0.17\text{W/m}\text{.K},\alpha =1.28\times {\text{ 10}}^{\text{-7}}{\text{m}}^{\text{2}}\text{/s)}$ and that is initially at a uniform temperature of 25°C is exposed to hot gases at 550°C for a period of 5 mm. The heat transfer coefficient between the gases and the wood slab is 35 W/m² K. If the ignition temperature of the wood is 450°C, determine if the wood will ignite.