Basics and Types

• Mechanical waves have the ability to move over large distances but the particles have limited movement. Particles vibrate back and forth about an average position -> transferring energy
• Pulse vs Wave

  Pulse - one singular motion

  Wave - a periodic up and down motion
• Periodic: there is continuous vibration at the source, causing the medium's particles to oscillate about their average position
• Travelling wave: a wave that travels unimpeded through a medium
• TRANSVERSE WAVES - particles vibrate up and down, perpendicular to the direction of motion
• LONGITUDINAL WAVES - particles vibrate in the same direction, parallel to the direction of energy flow

  E.g. Sound waves
• Compressions: areas of high pressure and compression

  Rarefactions: areas of low pressure and expansion
• Displacement-Distance graphs shows the displacement of particles at a moment in time, and are sinusoidal (take shape of sine wave)
• Amplitude (A): a particles maximum displacement from its average position
• Wavelength (λ): the distance of a whole phase

  Measured in m

  Phase: when two particles have the same displacement and are in the same motion
• Frequency (f): the number of complete cycles that pass a point per second

  Measured in Hz or s-1
• Displacement-Time Graphs track the position of one point over time as the wave moves through
• Period (T): the time it takes for any point to complete a full cycle

  Measured in seconds

  Period and frequency are inversely related

  $T=$$1/f$ or $f=$$1/T$
• WAVE EQUATION

  $v=$$fλ$ or $v=$$λ/T$