Light and sound

Light and sound

1. Light

   • Light travels in waves
     • Waves travel in straight lines
       • Waves are faster than sound waves
   • they are reflected by mirrors
     • They change direction when they travel from the air into a glass or water
   • 300 million metres per second
     • 8 Mins 20 secs to get from the sun to the earth
   • A million times faster than light
     • You see lightning before thunder

2. Sound

   • Produced by vibrations
     • Travel in waves that are vibrating
       • Waves are reflected by surfaces
   • For example when you bang a drum its skin vibrates
     • The harder you bang, the bigger the vibrations are
     • The vibrating drum skin causes nearby air particles to vibrate, which in turn causes other nearby air particles to vibrate too
     • These vibrating particles make up a sound wave
   • 343 metres per second
     • Faster through liquids and solids
   • Hard surfaces reflect sound well to create an echo