Heating and Cooling A2 46-53 Flashcards
What is the difference between temperature and energy store of a swimming pool and a glass of water
The glass of water and swimming pool can have the same temperature, but the swimming pool has a larger energy store.
What does the energy you need to increase the temperature of a metal depend on?
- The mass of the material
- What the material is made of
- The temperature rise you want
How do hot objects cool down?
Energy is transferred from the hot object to the cool object until both objects are of the same temperature.
Name the 3 pathways through which energy can be transferred.
- Conduction
- Convection
- Radiation
How does energy get transferred through particles in conduction?
Energy is transferrend through the collinding particles as they vibrate
Why is metal a good thermal conductor?
They have electrons that are free to move
What are thermal insulators?
Materials that very poorly conduct heat. Its not that they dont conduct heat at all, though.
Why are gases very bad thermal conductors?
The particles are much further apart than solids.
How do convectional currents work?
When you are heating a liquid, the particles closest to the heat source heat up and move faster apart, causing the liquid to be less dense. The particles move upwards, and cold particles rush in to take th eplace of the hot particles.
How do light and heat/infrared radiation travel?
As waves
What does the type of radiation emitted depend on?
The source’s temperature
How much radiation a source emits per second is depended by what?
The type of surface
What does a thermal imaging camera do?
Absorbs infrared and produces an image, reddening the areas which are hotter.
How can you slow down energy transfer in conduction?
Use a thermal insulator
How can you slow down energy transfer in convection
Use limited pockets of air that limit particle movement
