Waves

Waves

1. Mechanical

   • need a medium for its transmission
     • water, air, and sound
     • Longitudinal waves
       • sound waves
         • audible, ultrasound, doppler the effect, echos,
           • musical notes
             • pitch, loudness, harmonica, resonance, etc
     • Transverse waves
       • water waves
     • compressional wave
   • an example of mechanical waves are the ripples made in a pool when a stone is thrown

2. Electromagnetic

   • waves that have no medium to travel
   • disturbance waves
   • an example of electromagnetic waves are light and radio signals
     • radio
       • have longest wavelength, the lowest energy
     • micro
       • used for telecommunications
     • infrared
       • felt as heat

3. pulse vs periodic

   • pulse
     • a single wave
     • have assaulted the medium only once
     • not by frequency
   • periodic
     • periodic waves are a series of waves
     • are many and are continously assaulting the medium

4. transversal vs longitudinal

   • longitudinal
     • the displacement of the medium is parallel
     • sound waves in air are longitudinal waves
   • transversal
     • the displacement is perpendicular to the direction of propagation of the wave
     • cannot proppagate in gas or liquid

5. characteristics

   • crest/peak
     • highest point
   • trough
     • lowest point
   • wavelength
     • the distance between two places in a wave
   • amplitude
     • the maximum displacement from its middle position
   • frequency
     • the number of waves that pass a point each second
   • equilibrium line
     • the state of balance or resting point

6. wave interference

   • constructive
     • it occurs at any location along the medium where the two interfering waves have a displacement
     • they work to build a higher energy between the waves
   • destructive
     • two interfering waves have amplitudes in opposite directions

7. E=cte ·f2 ·A2

   • energy wave formula

8. υ = ∆x/t

   • speed equation

9. wave behavior

   • diffraction
     • bending of a wave around an obstacle or through an opening in an obstacle
   • reflection
     • bouncing back of waves from a barrier they cannot pass through
   • refraction
     • bending of waves as they enter a new medium at an angle and change speed
   • standing wave
     • wave appearing to stand still that forms when a wave and its reflected wave interference
   • wave interference
     • interaction of waves with other waves