WAVES

WAVES

1. Transverse waves

   • Travels in a direction
     • perpendicular in which the medium is vibrating
   • Concepts
     • amplitude
     • period
     • wavelength
     • frequency
   • a example: string
   • equations
     • a=-w²×A×cos(wt + δ)
     • V= -w×A×sin(wt + δ)
     • F= w/2π
     • W= 2π/t

2. sound waves

   • speed
     • At sea level
       • approximately 340m/s
   • is produced by:
     • vibration of an object

3. Superposition of waves

   • when two or more waves meet
     • overlap, the displacement of the string is equal to the sum of the individual displacements
   • Same sign when overlap
     • constructive interference
       • The combined wave will have a displacement of grater magnitud than either individual wave
   • opposite displacements
     • destructive interference
       • The combined wave will have a displacement of smaller magnitud than either individual wave

4. Standing waves

   • when the wave on a string hits the wall
     • the wave will reflect and travel back to us
   • each point on a string supporting a standing wave has an individual amplitude

5. waves rules

   • rule #1
     • The speed of th a wave is determined by the type of wave and the characteristics of the medium
       • Not by the frequency
   • Rule #2
     • When a wave passes into another medium, its speed changes
       • but its frequency does not.