Methods of Thermal Energy Transfer

Question 1

What is conduction

Answer 1

Happens when two objects of different temperatures are in direct contact

Heat is transferred from one particle to another when those particles collide.

Question 2

What is natural convection

Answer 2

Motion of fluid (liq or gas) caused by natural forces within it

Most common cause: buoyancy, hotter less dense, float up.

As fluid flows, forms convection current that carries thermal energy throughout fluid.

Question 3

What is forced convection

Answer 3

Describes motion of fluid caused by forces outside it.

Forces often move fluid faster or in a different direction compared to natural convection

Question 4

What is radiation

Answer 4

Consists of electromagnetic waves which transmit energy from source to absorber

Only transfer of heat that does not involve the movement of particles

Question 5

Radiation Properties

Answer 5

Objects can radiate and absorb radiation at the same time.

Objects with higher temp than surrounding radiate more than absorb, losing temp and vice versa

Smooth surfaces do not radiate or absorb as much as rough

Reflective do not radiate as much as black.

Question 6

What are conductors

Answer 6

A material where thermal energy flows through it quickly.

Metals are good conductors

Question 7

What are insulators

Answer 7

Material where thermal energy flows slowly

Most non-metallic materials