unit 8 waves
wave investigations
types of waves
wave speed
wave properties
different parts of a wave
superposition of waves
doppler effect
medium boundaries
standing waves
waves that appear to stand still but are actually made of waves reflecting and interfering with each other
speed of standing waves
wave investigations
types of waves
- transverse waves - oscillation is perpendicular to the direction of motion (rope waves, light waves)
- longitudinal waves - oscillation is parallel to the direction of motion (sound waves, pressure waves)
- mechanical - require a medium (sound waves, ocean waves)
- electromagnetic - waves that do not require a medium (light waves)
wave speed
- wave speed depends on the medium
- waves travel at a constant speed
- to keep constant speed double frequency and half wavelength
- increase tension - increase wave speed
- velocity = wavelength/period = λ/T = λ x f
wave properties
different parts of a wave
- amplitude - max displacement of oscillations in a wave (determines energy of wave) (more amp. more energy)
- transverse - max distance from equilibrium
- longitudinal - density of compression
- period - time between oscillations in seconds
- frequency - number of oscillations per unit of time (reciprocal of period)
- wavelength - distance between waves (between crests or compressions)
superposition of waves
doppler effect
- phenomenon that occurs when wave source moves toward
- toward source - smaller wavelength, higher frequency, higher pitch
- away from source - longer wavelength, lower frequency, lower pitch
- constructive - waves in phase add amplitudes together
- destructive - waves out fo phase amplitudes cancel out
- change in amplitude for two similar frequency waves
- beat frequency = f1 - f2
medium boundaries
- where wave ends depend on boundaries
- two fixed ends - wave ends on nodes on both sides
- one open end - one node and one antinode
- two open ends - two antinodes
- ruben's tube - sound is a longitudinal wave (areas of high pressure push gas out more)
standing waves
waves that appear to stand still but are actually made of waves reflecting and interfering with each other
- node - areas that aren't moving (total destructive interference)
- antinode - areas that move the most (total constructive interference)
- fundamental frequency - frequency of the most simple wave
- harmonics - integers of the fundamental frequency
speed of standing waves
- string tension will affect wave speed
- velocity = square root of string density divided by linear density
|
|