P6 Waves Flashcards
Waves
A way for energy to be transferred without transferring matter
How do waves transfer energy?
- The medium the waves travel through oscillate and transfer energy between each other, but overall stay in the same place
- Waves transfer energy in the direction they are travelling
Amplitude
The maximum displacement of a point on the wave from its undisturbed position
Wavelength
The distance from the same point on the two adjacent waves (usually the peak)
Frequency
The number of completed waves passing a certain point per second
Hz
Measures frequency
Transverse waves
- Oscillations are perpendicular to the direction of transfer energy
- All electromagnetic waves
- Ripples and waves in water
- A wave on a string
Longitudinal waves
Parallel to the direction of energy transfer
Wave speed eq =
Frequency * wavelength
What is used to measure the speed of sound?
Oscilloscope
What are the 3 things that can happen a wave meets a boundary between 2 materials?
- The wave is absorbed by the second material and transfers the wave energy to the material’s energy stores
- The wave is transmitted through the second material and the wave carries on travelling through the new material which often leads to refraction
- The wave is reflected, where it is not absorbed or transmitted. This is how echoes are created
What determines what happens to a wave at boundaries?
The wavelength and the properties of the material
Electromagnetic waves are what type of waves?
Transverse waves
Electromagnetic waves transfer energy from a … to an …
source (emitter), absorber
EM waves travel at …
the same speed through air or a vacuum (as they are vibrations of electric and magnetic fields)
Radio waves wl
1m - 10^4 m
Micro waves wl
10^-2 m
Infra red wl
10^-5 m
Visible light wl
10^-7 m
Ultra violet wl
10^-8 m