Waves

1
Waves

• Sound Waves

2
Review

• Waves have amplitude, velocity, wavelength,
  period and frequency
• Nodes and anti-nodes
• Two types of waves
• Longitudinal waves
• Transverse wave
• Interference
• Standing waves

3
Sound

• Longitudinal Waves
• Olliscope Representation
• Pitch, Frequency and Period
• Speed of Sound
• Interference
• Resonance
• Beats
• Doppler Effect

4
Longitudinal Waves

• Sound travels as a longitudinal wave
• Longitudinal waves are shown as compressions and
  rarefactions
• Relative maximum and minimums are shown parallel
  to the direction of travel

5
Olliscope Representation

• Longitudinal waves can also be represented as a
  transverse wave when using and olliscope
• Compressions translate to crests while
  rarefactions become troughs

6
Pitch, Frequency and Period

• The frequency of sound is commonly described as
  pitch
• Frequency and period vary inversely
• F 1 / P

7
Speed and Wavelength

• Speed of sound 331m/s (0.6m/s)Temp
• At room temperature (20 degrees Celsius), the
  speed of sound is 343m/s
• Wavelength speed / frequency

8
Interference

• Waves constructively and destructively interfere
  with one another without changing each other

9
Resonance

• When sound enters a tube, sound waves resonate
  depending on the length of the tube
• The resonant frequencies then become amplified
• Rubens Tube

10
Beats

• Beats occur when two waves with a slight
  difference in frequency interfere
• The result of the interference is a beat that is
  equal to the difference of the frequencies

11
Doppler Effect

• The Doppler Effect occurs when either the source
  or the observer has a velocity relative to one
  another
• The Doppler Effect is a shift in observed
  frequency as a result of

12
Sound

• Longitudinal Waves
• Olliscope Representation
• Pitch, Frequency and Period
• Speed of Sound
• Interference
• Resonance
• Beats
• Doppler Effect