Physics - Chapter 13

13.3 §

• Wave - disturbance that propagates or is transmitted from place to place carrying energy as it travels
• Waves travel place to place but particles in a wave oscillate
• Transverse Wave - particles oscillate at right angles to the direction wave travels
• Longitudal Waves - particles oscillate parallel to the direction of propagation
• $\lambda$ = Wavelength = distance over which a wave repeats
  • SI Unit: m
• speed = $\frac{wavelength}{period}$
  • v = $\frac{\lambda }{T}$
• speed = wavelength x frequency
  • v = $\lambda$f
  • SI Unit: $\frac{m}{s}$
• Medium - Any type of matter such as air, water, or steel
• Mechanical Waves - travel through matter

13.4 §

• Resultant Wave - 2 or more individual waves that overlap and as a result combine
• Principle of Superposition - Resultant wave is sum of individual waves that make it up
• Constructive Interference - When waves combine to form a larger wave
• Destructive Interference - When waves superpose to form a smaller wave
  • Used to reduce noises in factory, busy offices, and even airplane cabins
• Interference is one of the key characters that define waves
• Standing Wave - A wave that oscillates in a fixed location
• Nodes - Points on a standing wave that do not move
• Antinode - Maximum displacement between any 2 node points
• First-harmonic frequency for a string of length L is f${}_1$ = $\frac{v}{2L}$