Waves 1

Waves 1

1. Microwaves- used for satellite and phone communication

   • Radiowaves- television, radio, bluetooth
   • Infra-red- tv remotes, thermal cameras; felt as heat, can burn skin
     • Visible light- photography; too much can cause damage
       • Ultraviolet- security marking, sun beds; absorbed by skin, can cause skin cancer and blindness
         • X-rays- medical imaging of bones, airport security; cause cancer and can kill cells
           • Gamma rays- killing germs on surgical instruments; can cause cancer, mutations, can kill cells

2. diffraction- when waves bend after touching the edges of a gap;

   • will produce semi circles if the gap width equals the wavelength

3. interference- when identical waves meet they cancel out

4. frequency- the number of complete waves, hertz

5. CMBR- when the universe was young, it eventually allowed light to travel; now nearly 14 billion years of red shift have produced microwaves

6. wavelength- the length of 1 complete wave (meters)

   • the distance between 2 identical points on a progressive wave

7. Amplitude- the furthest that any particle is moved from its rest position by a wave

8. time period- the time for one complete wave; the inverse one over the frequency

9. Electromagnetic spectrum- a series of waves, all travelling at 3 x 10 to the power of 8