Here it is:On a hot day which would stay cool longer: a sheet of aluminum ( specific heat 920 J/kg K) or a sheet of copper ( specific heat 380 J/kg K)? Why?
The aluminum would stay cool longer. Firstly aluminum has a higher specific heat capacity so it takes a greater amount of heat energy to raise the temperature by 1K. Also copper has greater thermal conductivity so heat flows into it more readily and it would heat up quicker. This is why a metal object left on a table in the sun gets hot so quickly or why metal feels much colder than other objects in a room, e.g. a Styrofoam cup. Another possibility is that the aluminum because of its lighter color, may reflect more light and so absorb less heat.
