Waves 4.6.1 Flashcards
Wave properties, calculations and uses
Waves are categorised into two types: ________ and ________
Longitudinal and Transverse
What’s the difference between longitudinal waves and transverse waves?
- Longitudinal waves oscillate parallel to the direction of energy transfer
- Transverse waves oscilliate perpendicular to the direction of energy transfer
- Longitudinal waves need a medium to travel through
- Transverse waves do not need a medium to travel through
What is the time period of a wave?
The time taken to complete one oscillation
How do you calculate the frequency of a wave?
f = 1 / T
where f is frequency (Hz) ; T is time period (s)
How do you calculate the speed of a wave?
v = f × λ
where v is the speed (m/s) ; f is frequency (Hz) ; λ is wavelength (m)
What is defined by the maximum displacement of a point
on a wave away from the rest position?
The amplitude
What are the 3 things that could happen when a wave hits a boundary?
- Reflection, energy bounces back
- Transmission, energy passes through
- Absorbtion, energy is absorbed
What does the law of reflection state?
The angle of incidence = The angle of reflection
The range of human hearing is between ____ Hz and ____ Hz
20 and 20,000
Sound waves are a example of ____ waves
Longitudinal
Give an example of a transverse wave
- Water waves
- Seismic S-waves
- Any electromagnetic wave
Name the seismic waves produced by an earthquake
- P-Waves (primary)
- S-Waves (secondary)
- L-Waves (surface)
Why can P-Waves travel through the earth but not S-waves?
P-Waves are longtitudinal so can travel through the solid crust and liquid mantle, however S-waves are transverse so cannot travel through the liquid mantle.
What are the uses of ultrasound?
- Medical imaging
- Industrial quality control (detecting cracks)
- Sonar
