Question

Objects placed together eventually reach the same temperature. When you go into a room and touch a piece of metal in that room, it feels colder than a piece of plastic. Explain.

Short answer

At room temperature, the piece of metal feels colder than plastic because the metal piece will conduct heat from the hand and gives a cold sensation whereas plastic does not.

Step-by-step solution

Definition of room temperature

A comfortable temperature that is not too hot or cold is defined as room temperature. Generally, room temperature is taken as $\text{25}°\text{C}$.

A piece of metal feels colder than a piece of plastic at the same temperature.

As metals are very good conductors of heat, therefore the metal piece will conduct heat from the hand and gives a cold sensation. On the other hand, plastics do not conduct heat, therefore while touching plastic at the same temperature it feels relatively warmer.

Hence, at room temperature, the piece of metal feels colder than plastic because the plastic piece does not conduct heat (extract heat from hands) as metal does.