Waves

Waves

1. Frequency = number of complete waves passing a point per second = hertz Hz

   • Wave speed (m/s) = frequency (Hz) x wavelength (m)

2. Wave Properties

3. Light has a very small wavelength, so it can be diffracted but it needs a really small gap

4. Short waves reflect of the ionosphere

5. FM radio and TV signals must be in line of sight

6. Long-wave signals diffract (bend) around the Earth

7. Microwaves are used for satellite and mobile phones - microwaves are absorbed by water molecules and heat them up, this could happen to your brain when using a mobile phone

8. Sound Waves

   • Sound waves are longitudinal, sounds travel faster in solids than in liquids and faster in liquids than in gases
   • Echo
     • Sound waves will be reflected by hard flat surfaces
   • Sound waves will also refract (change direction) as they enter different media, as they enter denser material, they speed up
   • The higher the frequency the higher the pitch
     • High frequency = high pitch low frequency = low pitch
     • High frequency also means shorter wavelength
     • The loudness of a sound depends on the amplitude, the bigger the amplitude the louder the sound

9. The Origin of the Universe

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