Waves and Energy

Waves and Energy

1. Behaviour of waves

   • Reflection
     • Light bounces of a SMOOTH surface
     • Angle of incidence/Angle of reflection= Same
   • Refraction
     • Light slows down when passed through denser medium
       • It bends towards the normal in denser mediums then bends back in less dense mediums
         • Creates optical illusion
     • Light bends towards the normal (90 degrees)
     • APPLY TO ALL WAVES
   • Diffraction
     • Light is scattered when passed through a small gap- like water waves

2. Doppler effect

   • Wavelength increases when emmitter of waves is moving away
     • Sound gets lower pitched
     • can be detected in light as red-shift
       • Tells us galaxies moving away from us
         • Tells us universe is expanding
           • Evidence for big bang along with CMBR- Energy left over from big bang
   • Wavelength decreases when emitter of waves is moving toward you
     • Sound gets higher pitched

3. Characteristics of waves

   • Wavelength, Frequency, amplitude
     • speed (m/s) divided by wavelength (metres)= Frequency (hZ)
       • speed (m/s) divided by frequency (hz)= wavelength (metres)
         • frequency (hZ) multiplied by wavelength (metres)= speed (m/s)
   • Types of wave
     • Transverse
     • Longitudinal

4. EM spectrum

   • Granny's X-box Uses Volts In My Room
     • Gama
       • High frequency, low wavelength, high evergy
       • Killing cancer cells, cleaning doctot'rs equipment
     • X-ray
       • X-rays
     • Ultra-Violet
       • Tanning
     • Visible
       • Photographs
     • Infra-red
       • Detecting drugs
     • Microwave
       • Used in mocrowaves and phones
     • Radio
       • Low frequency, low energy high wavelength
       • Used on radios and tvs