Transverse waves - the oscillations travel up and down.
Oscillations - vibrations.
Electromagnetic (EM) waves - transverse waves that transfer energy from a source to an absorber. They travel at the same speed through air or a vacuum. EM waves form a continuous spectrum over a range of frequencies.
Refraction -waves cross a boundary between materials, the angle is changed.
Optical density - how quickly light can travel through it.
Radio waves - made up of oscillating electric and magnetic fields. Types of radio wave:
- Long-wave radio - wavelengths of 1-10km. Can be received at long distances, wavelengths bend around the curved surface of the earth.
- Short-wave radio - wavelengths of 10m-100m. Can be received at long distances. They reflect from the ionosphere.
- Bluetooth - uses short-wave radio waves.
- Medium-wave - reflect from the ionosphere.
Microwaves - used by satellites. Signal from a transmitter is transmitted into space, received by the satellite and bounced back down to earth.
Infrared Radiation - given out by all hot objects. Can be used to increase or monitor the temperature.
Optical fibres - thin glass or plastic fibres that can carry data over long distances.
Ultraviolet Radiation (UV) - found naturally in sunlight.
X-rays - pass easily through flesh but not so easily through denser material like bones or metal.
Gramma Rays - used in medicine in patients to kill cancer cells.
Black body - an object that absorbs all of the radiation that hits it.
EQUATION Wave Speed
Watch the video and have a go at writing out the steps of the practical.