Sound

Sound

1. Speed of sound = 340m/s

2. Sound is a form of energy

   • Sound is produced by vibrations
   • Sound needs a medium to travel through
     • Echoes are reflected sound
     • Ear detects sound vibrations
       • Very loud sounds cause damage to hearing
         • Speed of sound is slower than speed of light e.g. thunder and lightning

3. Experiment: Turn on bell – can hear it ringing Turn on vacuum pump Vacuum pump removes air from the bell jar, can see the bell ringing but can no longer hear it

4. Sound needs a medium e.g. gas, liquid or solid to travel through. It cannot travel through a vacuum