Year 10 Physics [4]

Year 10 Physics [4]

1. dispersion

   • spectrum = white light
     • each colour in spectrum, different refractive index
     • hence, disperse in prism

2. total internal reflection

   • semi circular block ◒
     • when angle of refraction is 90°
       • CRITICAL ANGLE
         • all light is reflected from boundry
           • TOTAL INTERNAL REFLECTION

3. refraction

   • angle of incidence=angle of reflection
     • i to r ratio
       • REFRACTIVE INDEX
         • n= sin i/sin r
   • ray of light goes from (optically) +dense to -dense medium. i.e air to glass

4. sound

   • amplitude
     • soft
     • loud
   • v=fλ
   • pitch and frequency
     • quick vibrations
       • high pitch & frequency
     • slow vibrations
       • low pitch & frequency
   • longitudinal wave
     • can't travel in vacuum
   • series of
     • compressions
     • rarefractions
   • can be diffracted
   • audible range (20-20000Hz)
     • + = ultrasound
     • - = infrasound
   • reflection
     • called echo
     • used by ships for water depth