Topic 1 Conduction and convection Flashcards
Conduction definition
The process when vibrating particles transfer energy to neighbouring particles
What is conduction
Particles in the part of an object being heated vibrate more and collide with each other
these collisions cause energy to be transferred between particles kinetic energy stores this is conduction
When does conduction stop
Continues throughout the object until the energy is transferred to the other side
What is thermal conductivity a measure of
Is the measure of how quickly energy is transferred through material
materials with high conductivity transfer energy between the particles quickly
Convection definition
Convection is when energetic particles move away from hotter to cooler regions
What can convection happen in
Liquids or gases
What is convection
When you heat a region of a gas or a liquid the particles move faster and the space between individual particles increases
this causes the density of the region being heated to decrease
because liquids and gases can flow
the warmer and less dense region will rise above denser cooler regions
What creates a convection current
A constant heat source
Example of convection
Radiators
What happens after the thermal energy reaches the other side of the object
It is then usually transferred to the thermal energy store of the surroundings or anything else that touches the object
What is thermal conductivity a measure of
How quickly energy is transferred through a material in this way
High thermal conductivity transfer energy between particles quickly
Energy transfer by convection
Energy transferred by heating to the thermal store of the liquid or gas. This energy is shared across the kinetic energy stores of the gas or liquid particles
Particles are able to move and when heated move faster and space between individual particles increase
Density of the region decreases
Warner less dense region will rise above denser cooler regions
What happens if there is a constant heat source
A convention current can be created
What does heating a room with a radiator rely on
Creating convection currents in the air
How radiators heat up the room
Energy is transferred to nearby air particles by conduction (air particles collide with radiator)
Air by radiator becomes warmer and less dense so move quicker
Warm air rises and replaces cooler air
Cooler air is now heated and the heated air transfers energy to surroundings then cools and becomes denser
Repeats
