Heat Flashcards
What is convection
Transfer of heat through Liquids and gases. Liquid and gas particles are free to move. Particles with more kinetic energy move from hotter regions to cooler regions, taking their thermal energy with them
What is heat
It is a form of energy
Latent heat
Causes a change in state and not a change in temperature heat is lost
Explain materials reaction to temperature change
Expand when heated and contact when cooled
What is conduction
Is the transfer of heat through a solid. Vibrating particles pass on extra kinetic energy (or heat) to neighbouring particles.
Insulators
Are materials that are poor conductors of heat
Explain radiation
The transfer of heat in rays from a hot object without needing a medium to pass through
What is the difference between heat and temperature
Heat is a form of energy and measured in joules
Temperature is a means of measuring hot and cold and is measured in celcius
What does hot water do
Rise
What surfeces absord and radiate heat better
Dark surfaces
Explain what happens to water at 4 degrees
If you heat water above 4°C it will expand.
If you cool water below 4°C it will expand.
Above 4°C water behaves like other liquids.
Below 4°C water behaves oppositely to other liquids.
Why does a larger amount of water stay hotter than a smaller amount of water at the same temperature
A small volume of boiling water has the same temperature as a large volume full of boiling water. The large volume of boiling water has much more energy so stays warm longer
Why did the copper rods pin fall off first in the experiment To show the transfer of heat energy by conduction in solids
Copper is the best conductor of heat and melted the vaseline
Explain convection currents
The rising and falling of particles with more/less thermal energy results in a convection current
