🌡️ 2C — Heat Transfer

In what direction does heat transfer naturally occur?

From warmer objects to cooler objects.

What happens when two objects reach the same temperature?

They no longer transfer heat between each other.

What factors affect heat transfer rate?

The temperature difference between bodies and the thermal conductivity of the material.

What are the three mechanisms of heat transfer?

Conduction, convection, and radiation.

What is conduction?

The transfer of heat through and between solids.

How does conduction occur?

Molecular motion and collisions transfer energy throughout a substance.

What factors affect conduction?

The area being heated, temperature difference, and thermal conductivity of the material.

Why is air a good insulator?

Air has poor thermal conductivity because its molecules are relatively far apart.

What is convection?

The transfer of thermal energy by movement or circulation of a fluid, such as a liquid or gas.

What does convection usually involve in a fire?

The movement of hot smoke and fire gases.

What causes vertical movement of fire gases?

Buoyancy.

What causes lateral movement of fire gases?

Pressure differences that move gases from high to low pressure.

What factors affect convection?

The heated area, temperature difference, and turbulence and velocity of moving gases.

What is radiation?

The transmission of energy as electromagnetic waves without requiring an intervening medium.

What is an important example of radiation?

Heat from the sun traveling through space to warm Earth.