L6 - thermal energy transfer

Question 1

define ‘conduction’.

Answer 1

only happens in solids.

Question 2

define ‘convection’.

Answer 2

only happens in fluids (liquids and gases).

Question 3

define ‘radiation’.

Answer 3

does not use particles, pure heat energy, can occur anywhere (even in a vacuum).

Question 4

why does the temp of metal increase when heated?

Answer 4

electrons free to move and transfer thermal energy, collide with particles in metal which increases kinetic energy, vibrations passed onto the particles next to it.

Question 5

define ‘thermal conductivity’.

Answer 5

a measure of the rate of thermal energy transfer. different materials have different thermal conductivity.

Question 6

the energy transfer per second through a layer if insulating material depends on..

Answer 6

the thermal conductivity of the material, the thickness of the material, the temperature difference across the material.