1.8 - conduction, convection & radiation

Question 1

which type of energy can be transferred by conduction, convection, or radiation?

Answer 1

Thermal energy.

Question 2

what physical state(s) does conduction take place in?

Answer 2

solid.

Question 3

which physical state(s) does convection take place in?

Answer 3

fluids - liquid and gaseous states.

Question 4

what is thermal conductivity?

Answer 4

a measure of how well a material conducts thermal energy when it is heated.

Question 5

outline the steps of how conduction works.

Answer 5

1. As one end of a solid object is heated, heat energy is transferred to the kinetic energy store of the particles in that end.
2. This causes the particles to vibrate faster, so they collide with neighbouring particles more frequently.
3. The collisions transfer kinetic energy, meaning the neighbouring particles also vibrate faster - and in turn collide more frequently with their neighbours.
4. This process repeats - energy is passes along the object, from one particle to the next.
5. either heat or thermal energy is transferred.

Question 6

outline the steps of how convection works.

Answer 6

1. As a fluid is heated, the particles gain kinetic energy, and spread apart.
2. This means the heated fluid is less dense, and so it rises above the cooler fluid.
3. As the fluid cools down it becomes more dense again, and so sinks below any warmer fluid.
   4, This process occurs in a limited space, such as a container or room, it may create a convection current.

Question 7

describe how heat transfer via radiation works

Answer 7

all objects emit and absorb energy via infrared radiation. Energy can therefore be transferred by one object emitting infrared radiation and another object absorbing it.