Question

1. using a heat lamp on different colored surfaces.
2. putting different metal blocks in cold water.
3. seeing how long it takes hot air to move across a room.
4. using a hot pan to melt different substances.

which examples show that energy is transferred by conduction?
a. 1 and 2
b. 2 and 3
c. 2 and 4
d. 3 and 4

Explanation:

• Conduction is the transfer of heat through direct contact.
• In "Putting different metal blocks in cold water", heat is transferred from the metal (higher - temperature object) to the water (lower - temperature object) through direct contact.
• In "Using a hot pan to melt different substances", heat is transferred from the hot pan (higher - temperature object) to the substances (lower - temperature objects) through direct contact.
• "Using a heat lamp on different colored surfaces" involves heat transfer by radiation (heat transfer via electromagnetic waves).
• "Seeing how long it takes hot air to move across a room" involves heat transfer by convection (heat transfer due to the movement of fluids - in this case, air).

Answer:

C. 2 and 4