Waves Flashcards
Wavelength
The distance from one peak to the next
Frequency
How many complete waves there are per second, measured in Hertz (Hz)
Amplitude
The height of the wave from rest to crest
Period
The time (in seconds) for one complete wave to pass a point
Wave speed equation
Wavelength x frequency
Transverse waves
Waves where the vibrations are at a 90 degree angle to the direction energy is transferred by the wave
Examples of transverse waves
1) Light and EM waves
2) A slinky moving side to side
3) Ripples on water
4) Waves on strings
Longitudinal waves
Waves where the vibrations move in the same direction as energy transferred by the wave
Examples of longitudinal waves
1) Sound and ultrasound
2) Shockwaves e.g. seismic waves
3) A slinky moving back and forth
What do waves transfer?
All waves transfer energy and information in the direction they’re travelling but not matter
Wave fronts
1) Imaginary planes that cut across the waves, connecting the points on adjacent waves which are vibrating together.
2) The distance between each wave front is equal to one wavelength.
The Doppler effect
1) The waves produced by a source which is moving away from the observer will appear to have a different wavelength than if the source were stationary.
2) This is because the wave speed is constant, so if the source is moving, it ‘catches up’ to the waves in front of it.
3) This causes them to bunch up in front of the moving source and spread out behind it.
4) The frequency of a source moving towards you will seem higher and its wavelength will seem shorter
5) The frequency of a source moving away will seem lower and its wavelength will seem longer.
The seven types of EM waves
Richard=radio waves Made=micro waves In=infra-red waves Very=visible light (ROYGBIV) Utmost=ultraviolet X=x-rays Games=gamma rays
What type of wave are all EM waves
1) Transverse waves.
2) They travel at the same speed through a vacuum.
Wavelengths of visible light
Red has the longest wavelength and violet has the shortest wavelength
