# Waves.

## Presentation on theme: "Waves."— Presentation transcript:

Waves

What is a wave?  - a repeating disturbance or movement that transfers energy through matter or space Examples: ocean waves light sound

Waves travel through matter - this is called the MEDIUM
Mediums can be - solid  (earth) - liquid (water) - gas  (air) Light and radio waves travel through space and do not need a medium.

Electromagnetic Waves
these are made by vibrating electrical charges that can travel through space where matter is not present They do NOT require matter to move through

Transverse Waves - medium moves at a right angle to the direction of the wave (like in the ocean)
Compression waves - medium moves along the same direction as the wave, visualize a coiled spring.

The Parts of a Transverse Wave
The high part of the wave is the CREST The low part of the wave is the TROUGH

The Parts of a Transverse Wave
Wavelength = the distance from one point of the wave to the next point (from crest to crest, or from trough to trough)

The Parts of a Transverse Wave
FREQUENCY =  number of waves that pass a point in a second Frequency is measured in hertz (Hz) Each wave has a PERIOD, which is the amount of time it takes for one wavelength to pass a point

If you make transverse waves by moving a rope up and down, you can increase the frequency by moving the rope faster. This makes the wavelength SHORTER high frequency = short wavelength low frequency = long wavelength

Wave Speed - how fast a wave travels    Speed (m/s) =  frequency (Hz)  x wavelength (m)
Greek letter lambda is used to represent wavelength

Wave Amplitude Amplitude is related to the amount of energy a wave carries. Tighter packed coils of the slinky will cause greater energy. In the rope, raising the hand higher and causing "bigger" waves increases the amplitude Amplitude = height of wave

Bill Nye Episode #51.