Based on the principles of convection, conduction and thermal radiation, which scenario below is most similar to the following situation?

You put a heating pad on your back after exercising.
Responses
A Feeling a metal wire get warmer as you roast a marshmallow over a fire.Feeling a metal wire get warmer as you roast a marshmallow over a fire.
B Warm air rising in a room where the air is moving.Warm air rising in a room where the air is moving.
C The sun warming up the roof on a house.The sun warming up the roof on a house.
D Cold water sinking in a pot of water being warmed up on the stove.

1 answer

The best scenario that is most similar to putting a heating pad on your back after exercising is A: Feeling a metal wire get warmer as you roast a marshmallow over a fire.

Here's why:

  • When you place a heating pad on your back, heat is transferred to your body primarily through conduction, as the heating pad is in direct contact with your skin.
  • In scenario A, the metal wire gets warmer due to heat conduction from the fire to the wire, similar to how the heating pad transfers heat to your back.

In contrast:

  • B (warm air rising) and D (cold water sinking) are related to convection, where heat is transferred by the movement of fluids (gases or liquids).
  • C (the sun warming a roof) is an example of thermal radiation, where heat is transferred through electromagnetic waves without direct contact.

Therefore, for the direct transfer of heat through contact like the heating pad scenario, option A is the most similar.