Question

A vertical plate and a horizontal plate are suspended in an open room. Both are heated to the same temperature. Which one will cool first? Why?

Answer 1

As per cooling is considered both will cool at the same rate because there is no physical difference between them.

If you supply air in the horizontal plane the vertical plate will cool first.

If you supply air in vertical plane then horizontal plate will cool first.

For last two cases, the reason is surface area. More the surface area, more the cooling rate.