P1.1 Flashcards
What are dark, matt surfaces good at?
Good absorbers of infrared radiation. Good emitters of infrared radiation.
Particles in a solid are?
The particles vibrate about fixed positions so the solid has a fixed shape.
Particles in a liquid are?
Are in contact with each other but can move at random, so liquid doesn’t have fixed shape and can flow.
Particles in a gas are?
Far apart and move at random much faster, so a gas doesn’t have a fixed shape and can flow. Density of gas much less than solid/liquid.
What is conduction?
Transfer of energy from particle to particle in matter. (Conduction in metal due to free electrons transferring energy).
What is convection?
Circulation of a fluid (liquid or gas) caused by heating it.
What is infrared radiation?
Energy transfer by electromagnetic waves.
What is evaporation?
A liquid turns into a gas. It takes place because the most energetic liquid molecules escape liquid’s surface and enter the air. So, average kinetic energy of remaining molecules is less, so temp decreases.
The greater the temperature difference between an object and its surroundings?
The greater the rate at which energy is transferred.
The greater the mass of an object?
The more slowly its temperature increases when heated.
What is the U-value?
Tell’s how much energy per sec. passes through different materials. The lower the U-value, the better the material is as an insulator.
Solar heating panels?
Contain water heated by sun. Cheap to run as don’t use fuel, but expensive to buy/ install and do not heat at night.
