Waves transfer energy in the direction they are travelling.
Amplitude - maximum displacement of a point on the wave.
Wavelength - distance between the same point on two adjacent waves.
Frequency - the number of complete waves passing a certian point per second.
Hertz (Hz) - the measurement of frequency.
Oscillations - vibrations.
Transverse waves - the oscillations travel up and down.
Longitudinal waves - the oscillations in the same direction as the wave travels.
Waves can be:
- Absorbed - this transfers energy to the material's energy stores.
- Transmitted - waves travel thorugh the new material.
- Refraction -waves cross a boundary between materials, the angle is changed.
Specular reflection - wave is reflected in a single direction.
Diffuse reflection - wave is reflected by a rought surface and scattered in different directions.
Sound waves - caused by vibrating objects.
Parts of the ear:
- Ear drum - vibrates as sound waves reach.
- Ossicles - receive the vibrations from the ear drum.
- Cochlea - turns vibrations to electrical signals which then get sent to your brain.
Ultrasound - sound with frequencies higher than 20,000Hz.
Echo sounding - used by boats and submarines, use high-frequency sound waves including ultrasound.
Seismic waves - produced by earthquakes which out through the Earth.
Seismometers - detect seismic waves over the surface of the planet.
Seismologists - study seismic waves to work out the time it takes for the shock waves to reach each seismometer.
P-waves - longitudinal waves that travel through solids and liquids and speeds faster than S-waves.
S-waves - transverse waves that can't travel through liquids or gases.
PRACTICAL Waves in a ripple tank
Watch the video and have a go at writing out the steps of the practical.
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