sound waves

sound waves

1. caused by vibrating objects, these mechanical vibrations are passed through a surrounding medium as a series of compressions, they're a longitudinal wave(vibrations along a straight line)

2. generally travel faster in solids then liquids then gases

   • due to the particles been closest in solids then liquids then gases
     • can't travel in space - its a vaccum

3. can reflect and refract

   • sound waves will be reflected by hard, flat surfaces
     • very noticeable in empty room: without furnishings it echoes but with furniture etc the sound waves are absorbed quickly so they can't echoe
       • echoes are reflected sound waves and are delayed from the original sound as they have to travel further
   • sound waves also refract(change direction) as they enter different media(material) when entering denser materials they speed up as particles in denser media are closer together(this speeding up is hard to spot in normal circumstances as sound waves are always spreading out so much.

4. higher frequency = higher pitch + shorter wavelength

   • frequency is number of complete vibrations each second so frequency of 100Hz = 100 vibrations a second
     • frequency measured in Hz - kHz(1000 Hz) - MHz(1,000,000Hz)

5. bigger amplitude = louder sound