AQA Core Physics | Energy Transfer by Heating

Infared Radiation

-Every object emits infared radiation.

-Radio waves, microwaves, infared radiation and visible light are parts of the electromagenetic spectrum. Electromagnetc waves are electric and magnet waves that travel through space and transfer infared radiation.

-The sun emits all kinds of electromagnetic radiation, most of which is blocked by the earths atmosphere, but not infared radiation.

-The earths atmosphere acts like a greenhouse, allowing short wavelength infared radiation and light from the sun to enter the atmosphere, but not allowing it back out, as objects emit infared radiation of longer wavelengths.

-The earth is becoming too warm because of all the gas and heat trapped inside.

-Dark, matt surfaces emit more infared radiation that light, shiny surfaces.

-Dark, matt surfaces absort more infared radiation than lightm shiny surfaces.

-Light, shiny surfaces, reflect more infared radiation than matt, dark surfaces.

States Of Matter

- A solid

. Does not flow, has a fixed volume and shape, and a much higher density than gas.

-A Liquid

.Flows, fits into its container shape, has afixed volume, and a much higher density than gas

-A Gas

.Flows, fills its container, can change colume, and has a low density

-

-Particles in a solid are held together in a fixed postion and they vibrate in these to keep their foxed shape.

-Particles in a liquid can move about at random but are still in contact with each other. This means it doesnt have a fixed shape and can flow.

-Particles in a gas move about at random much faster and are much further apart from each other, lowering the density of the gas.

-Particles in a gas have more energy than in a liquid, and a liquid more than in a solid.

Conduction

-Metals contain a lot of free electrons. These electrons move about at random inside the metal and hold the postive metal ions together and collide with other particles.

-Metals are the best conductors of energy bevause of their free electrons.

-Materials such as wool are the best insulators of energy.

-Non metals are poor conductors because they do not contain free electrons.

Convection

-Convection happens when we heat a fluid (Liquid or gas). Convection is the circulation of a fluid by heating…