Flashcards in Heat Energy Deck (12):
What is conduction?
The process of vibrating particles transferring energy into neighbouring particles
How does conduction work?
Energy is transferred to an object by heating is transferred to the thermal store of the object. This energy is shared across the kinetic energy stores of the particles in the object.
The particles vibrate and collide with each other. The collisions cause energy to be transferred between particles.
How does conduction heat surrounding objects?
The collisions cause energy transfer to the other side of the object. It then transfers to the thermal energy store of the surroundings.
What is thermal conductivity?
This is a measure of how quickly energy is transferred through a material in this way.
High thermal conductivity means quick energy transfer between particles
What is convection?
Convection is where energetic particles move away from hotter to cooler regions.
How does convection work?
Happens in gases or liquids.
Heat is transferred to the thermal store of the liquid or gas.
Energy is shared across the kinetic energy stores of the particles
Why does convection work in gas and liquids?
The particles can move. When heated the particles move faster and they spread out. The density decreases. Liquids and gases can flow so the less dense region rises above denser cooler regions so energetic particles move away from hotter to cooler regions.
Examples of convection:
Examples of conduction:
Cooking hobs and saucepans
What is radiation?
This heat transfer does not need particles. It can happen in a vacuum.
Radiation is affected by the colour of surfaces. Darker surfaces absorb heat energy. Lighter surfaces reflect heat energy.
Examples of radiation: