Physics Revision

Physics Revision

1. The Doppler Effect

   • The Doppler Effect is when sounds change wavelength and frequency depending upon whether it is moving away or towards something.
     • Moving towards a person
       • Shorter wavelength
       • Higher Frequency
       • Higher pitch
       • Waves are bunched up
     • Moving away from a person
       • Wavelength getting longer
       • Lower Frequency
       • Lower Pitch
       • Waves are more spread out

2. Redshift

   • Violet
     • Indigo
       • Blue
         • Green
           • Yellow
             • Orange
               • Red
                 • Richard
                 • Long Wavelength
                 • Low Frequency
               • Of
             • York
           • Gave
         • Battle
       • In
     • Vain
     • Short Wavelength
     • High Frequency
   • Redshift is when light is stretched to a longer wavelength, this lowers the frequency. The spectral lines shift to the red end of the spectrum. This proves the galaxies are moving away from each other and the universe is expanding.
   • Blueshift is when the wavelength of light compressed to a shorter wavelength/higher frequency. Spectral lines shift to the blue end of the spectrum. The galaxies would be moving towards each other.

3. The Big Bang Theory

   • It states that the Universe began from a very small, very dense and very hot initial point. It burst outwards in a great explosion, and all matter and space was created in The Big Bang.
   • The Big Bang happened approximately 13.7 billion years ago.
   • CMBR
     • CMBR is heat left over from the big bang.
     • CMBR can only be explained by The Big Bang.
     • Cosmic Microwave Background Radiation

4. Waves

   • Transverse
     • In TRANSVERSE waves the vibrations are PERPENDICULAR (90') to the DIRECTION OF ENERGY TRANSFER of the wave.
     • Examples
       • Light and all other EM Waves
       • Ripples on water
       • Waves on strings
       • Slinky spring wiggled up and down.
   • Longitudinal
     • In LONGITUDINAL waves the vibrations are PARALLEL to the DIRECTION OF ENERGY TRANSFER of the wave.
     • Examples
       • Sound waves and ultrasound
       • Shock waves e.g. seismic waves
       • Slinky spring when you push the end

5. EM Waves and Communication

   • Radio Waves
     • Micro waves
       • Infra red
         • Visible Light
           • Ultra Violet
             • X-Rays
               • Gamma rays
                 • Gorillas
                 • Shorter wavelength Higher Frequency
               • Exterminate
             • Underpants
           • Violet
         • In
       • Monkeys
     • Randy
     • Longer wavelength Lower Frequency
   • All the different types of EM waves travel at the same speed (3x10 to the power of 8m/s) in a vacuum.