On a cold day, why does a metal doorknob feel colder than the wooden door?
Solution 1E There is a thing called thermal diffusivity which is defined as the rate at which an object can transfer heat. The objects with high thermal diffusivity transfer heat at a very high rate and the objects with less thermal diffusivity transfer heat at a slower rate. When you touch a metal knob whose thermal diffusivity is very high, the heat from your hand gets transferred to the metallic knob at a much faster rate. So as the heat of your hand goes out, you feel cold. If you touch a non metal whose thermal diffusivity is less it feels hotter. But the irony is, you feel the same thing even the surface temperature for both the metal and nonmetal are same. It does not show that the temperature of metal is less and for nonmetal it is high.