GCSE Edexcel Physics 5.HT - Electromagnetic Waves

The wave can be:
Transmitted
Absorbed
Reflected
Refracted

The wavelength of the wave
The material the wave is travelling through

The slower the wave

Different wavelengths slow down by different amounts in the same material
So different wavelengths of light will refract by different amounts and seperate
Violet light is refracted the most
Red light is refracted the least

When an object absorbs and emits thermal radiation at the same rate
It will remain at a constant temperature

It gets hotter and will emit more radiation

It gets colder and will emit less radiation

Earth absorbs thermal radiation from the sun
The earth emits its own thermal radiation into space
Gases in the atmosphere absorb and reflect/emit some of this radiation back to earth

Surface of the sun is hotter than surface of the earth
Therefore, wavelength from sun has shorter wavelength (higher energy = higher frequency = lower wavelength)

Natural process that warms the earth’s surface.
Greenhouse gases: methane, carbon dioxide

By an antenna with a high frequency AC power source.

Charge oscillates up and down antenna
Producing radio waves

Metal aerial absorbs radio waves
Creates an alternating current with the same frequency as wave