Sound . (Physics)

Sound . (Physics)

1. Molecular Vibration

   • The molecules of the matter around the vibrating object transmit the sound energy.

2. Average speed of sound

   • Soild
     • 6000m/s
   • liquid
     • 1500m/s
   • gas
     • 330m/s

3. Ear

   • sensitive device which function hearing
   • allows to convert audible frequencies into electric signals
   • classified into outer , middle and inner ear
     • middle ear consist of 3 bones
       • hammer
       • anvil
       • stirrup
   • pinna collects sound from surroundings and passes through auditory/ear canal
   • vibration of eardrum amplified many times by these ear bones, turn into electric signals by cochlea, which passed through auditory/ear nerve to brain and the brain interprets them as sound

4. sound travel

   • when object vibrates,it passes energy to surrounding molecules
   • this causes layers of air to form compression and rarefaction
     • Compression is where air molecules are closer together
     • rarefaction is where air molecules are further from each other

5. For Entertainment

   • audible range of human being
     • 20-20000Hz
   • pleasant sound that soothing to the ear
   • things to enhance their experience
     • expensive headphones, noise cancelling function. expensive sound system

6. For warning signals

   • ambulance , traffic police car , fire alarm , lift breakdown, hissing from snakes

7. noise

   • unpleasant sound and even harmful
   • ear drum tissue destroyed, hearing loss or impairment , tinnitus , distractions that lead to accidents

8. sonar.

   • Sound Navigating and ranging
   • gather info about environment
   • transducer on boat sends out sound waves that expand as they travel, forming a cone, up to 50 Hz
   • reflect off structures and fish and receiver picks up returning sonar waves
   • signal about depth of sea and boats underwater or fish when in water
   • this is known as echolocation. where they use echoes to locate objects

9. ultrasound

   • >20000Hz

10. sound travel through air

    • when object vibrates, it pushes or pulls the surrounding air molecules which the layer formed compression and rarefaction