Properties of Waves Flashcards
Transverse wave
- oscillations of the wave are perpendicular to the direction the wave is travelling in
- particles move up and down
Example of a transverse wave
- seismic waves and light waves
Longitudinal waves
- oscillations of the wave are parallel to the direction the wave is travelling in
- particles move from side to side
Example of longitudinal wave
- sound waves
- ultrasound waves
Amplitude
Maximum height of the wave from the middle of the wave to the peak or trough
- measured in cm
Wavelength
Distance from peak to peak or through to trough
- measured in cm
Wavefront
Way of picturing waves from above
Frequency
Number of waves passing a certain point per second
- measured in hertz
Period
How long it takes for one complete wave to pass a point
- measured in seconds
What do waves transfer
Waves transfer energy and information without transferring matter - the points on the wave vibrate back and forth about fixed points
Relationship between speed, frequency and wavelength
Wave speed = frequency x wavelength
V = f x λ
Relationship between frequency and time period
Frequency = 1/ time period F = 1/T
What are waves
Waves are a series of vibrations or oscillations which travel through space
What is the Doppler effect?
Change in the observed frequency and wavelength of a wave when it’s source is moving relative to an observer
Explanation of Doppler effect
Wave fronts compress together in front of the moving source, and spread out behind the moving source
Refraction
When waves enter a different medium (e.g. glass or water) their speed can change, and the wavelength of the waves can increase/decrease, and the waves can change direction
Incidence and reflection
Angle of incidence = angle of reflection
What happens when waves slow down (refraction)
- when water travels from deep areas to shallow areas they slow down
- the waves will bunch together and cause the wavelength to decrease
- they will travel closer to the normal
What happens when waves speed up (refraction)
- they will spread out and cause the wavelength to increase
- the waves will turn slightly away from the normal
What is refraction
It is the name given to the change in speed of a wave when it passes from one medium to another
