Waves

Waves

1. Here's what and how you measure things on a wave:

2. There are two types of waves: transverse and longitudinal

   • Transverse waves
     • The vibrations are PERPENDICULAR to the direction of the energy
     • Examples
       • All EM Waves
       • Ripples on water
       • Waves on strings
     • They don't require any medium to travel through
   • Longitudinal waves
     • The vibrations are PARALLEL to the direction of energy transfer
     • Examples
       • Sound and ultrasound
       • Shock waves e.g. seismic waves
       • A slinky spring when the end has been pushed
   • Mechanical waves
     • They are he only types of wave that require a medium to travel through

3. The wave equation:

   • And its triangle:

4. All waves can be reflected, refracted and diffracted

   • Reflection
     • This is what allows us to see things
     • When light reflects of an uneven surface, the rays reflect at different angles
     • However, when it reflects of a smooth surface (like a mirror), it is reflected at the same angle
     • Angle of incidence = angle of reflection
   • Refraction
     • Changing the speed of a wave can change its direction
     • When a wave crosses through two different mediums, it changes direction
     • The only exception to this is if the wave hits the second medium along the normal
   • Diffraction
     • It pretty much means waves spreading out
     • The amount of diffraction is dependant on the size of the gap it has been passed through
       • Light can't be diffracted through a door frame as it has a very small wavelength
       • Sound can be because it has a wider wavelength so has maximum diffraction.

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