Heat Transfer Theory

Question 1

What are the three ways heat energy can be transferred?

Answer 1

1. Conduction
2. Convection
3. Radiation

Question 2

Describe conduction

Answer 2

Heat is transferred through the contact of bodies.

The particles are vibratting quickly and so are colliding with one another which transfers energy through the collisions

Question 3

Describe convection

Answer 3

Heat is transferred through the bulk movement of a fluid. Works off the rule of thermal expansion

One part of the fluid is heated which causes it to expand becoming less dense. The cold part is more dense and so sinks down causing the less dense, warm region to rise and move through the fluid.

The cold part is now in the place of the hot part and is being heated causing the cycle to repeat

Question 4

Describe thermal radiation

Answer 4

Heat is transferred through the emitting of electromagnetic waves

All objects simultaneously emit and absorb radiation.

A body emits the same amount of radiation as it absorbs

Question 5

What is a black body?

Answer 5

A perfect emitter/absorber of radiation