4.4 - Wave Characteristics

4.4 - Wave Characteristics

1. 4.4.1

   • Wave pulse- a single, instant crest?
   • Continous wave- A wave of constant amplitude and frequency; the wave goes up and down forever (unless damped!)

2. 4.4.3

   • Transverse wave- A wave in which the direction of disturbance is perpendicular to the direction of travel
     • Example: Wave in a string
   • Longitudinal wave- A wave in which the direction of disturbance is parallel to the direction of travel
     • Example: Wave in a spring

3. 4.4.2

   • Progressive waves transfer energy.

4. 4.4.4

   • Wavefront- a line joining all point in a wave that are in phase
   • Ray- lines drawn to show the direction of the wave, perpendicular to the wavefront

5. 4.4.5

   • Crest- maximum positive displacement from equilibrium position. Top of the wave
   • Trough- maximum negative displacment from equilibrium position. Bottom of the wave
   • Compression- pushing together of a longitudinal wave, increased frequency, decreased wavelength
   • Rarefaction- spreading out of the longitudinal wave, decreasing frequency, increased wavelength

6. 4.4.6

   • Wavelength- distance between two consecutive points of a wave that are in phase
   • Wave speed- distance travelled by the wave profile per unit time
   • Intensity- Power transferred by a wave per unit area

7. 44.8

   • If frequency is f, the time taken for a wave to pass one cycle is 1/f.
     • Velocity = distance over time
       • The distance moved in one cycle is one wavelength
         • So the velocity of a wave is the wavelength divided by 1/f, which is equal to the wavelength times the frequency

8. 4.4.9

   • All electromagnetic waves thravel with the same wave speed in free space!