Question

How does the size and shape of a material impact how it ignites?

Answer 1

Shape affects the ignition and behavior of fire much the same as size. Flat shaped fuel is similar to small size fuel in that it has a larger surface-to-volume ratio. It dries out faster and there is also more surface area for the heat to enter, thus it will ignite more readily because it takes less heat to dry it out.

Answer 2

Thinner materials tend to burn faster because the fire would be able to reach oxygen better, due to the fact that more of the mass would be exposed to the oxygen