Waves
- Created by: JessicaGrey
- Created on: 20-04-16 16:15
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- Waves
- Types of waves
- Longitudinal; oscillation is parallel to transfer of energy
- eg sound and seismic waves
- Needs a medium (particles)
- Key words; compression and rarefraction
- Transverse; oscillation is perpendicular to transfer of energy
- eg light, radio, rope and water waves
- No medium needed (can travel through a vacuum)
- Key words; peak, wavelength, frequency, amplitude and trough
- Longitudinal; oscillation is parallel to transfer of energy
- Frequency= waves per second
- Diffraction- spreading out of waves eg a gap in the wall.
- A gap size similar to the wavelength causes a lot of spreading
- A gap size much larger than the wavelength causes little spreading
- Refraction- waves change direction and speed when they change substance eg glass and air.
- think of tractor moving on pavement and mud
- The Electromagnetic Spectrum
- Gamma, xrays, ultraviolet, visible light, infrared, microwave, radiowaves
- "Granny's Xbox Uses Volts In My Room"
- Gamma Rays
- High frequency, short wavelength
- Radiowaves
- Low frequency, long wavelegth
- The wavelengths vary from about 10^(–15) metres to more than 10^(4) metres.
- All travel at the same speed through a vacuum
- Gamma, xrays, ultraviolet, visible light, infrared, microwave, radiowaves
- Communication
- Radiowaves
- Tv signals
- Bluetooth
- Radio
- Microwaves
- Phones
- Satellite Tv
- Infrared
- Remote controls
- Fibre optic cables
- By using these waves there is no loss of signal- clear image
- Visible light
- Fibre optic cables
- By using these waves there is no loss of signal- clear image
- Cameras
- Fibre optic cables
- Radiowaves
- Reflection
- Angle of incidence= angle of reflection
- The image produced in a plane mirror is virtual
- Sound
- Echos are sound wave reflected
- Frequency= pitch
- Amplitude= loudness
- Sound waves are longitudinal waves and cause vibrations in a medium, which are detected as sound
- Red Shift
- Doppler Effect
- If a wave source is moving relative to an observer there will be a change in the observed wavelength and frequency.
- Red stars are moving away
- Proof that the universe is expanding
- Cosmic microwave background radiation (CMBR)= electromagnetic radiation filling the universe.
It comes from radiation that was present shortly after
the beginning of the universe
- The ‘Big Bang’ theory is currently the only theory that can explain the existence of CMBR
- Doppler Effect
- Types of waves
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