FE Physics
 Formulas & Explanation
 
  Home
  Links
  Disclaimer/copyright
  Tell a friend
  Contact

 


Dutch version

Waves

 

Travelling waves

A periodic wave is a periodic disturbance that moves through a medium.

The vibration of the source is transmitted to other particles.

The particles of the rope (or spring) perform the same movement after another.

Amplitude is equal for all particles as the wave is undamped

All particles vibrate with the same frequency

 

Wave length :

a.           smallest distance between pairs of corresponding point on the wave train  

b.      distance that the wave moves in 1 periodic time

 

Transverse waves  :    direction of the particles in periodic motion perpendicular to the            

                                        direction in which the waves travel        

 

 

 

 

 

 

 

 

 

 

   

    

                                        

 

 

                                                                                           

                                      

 

                                       Example :  simple harmonic motion travels in a rope. 

                                                           the rope  takes the form of a sine

                                                           wavelength: length of 1 sine 

 

 

 

  

 

 

  

 

 

 

 

 

 

 

 

Longitudinal waves: direction periodic motion of the particles is the same

                                           direction in which the waves travel. 

                                      

 

 

                                    

 

                                    

 

 

 

 

 

 

 

 

 

 Example:  wave travels in air

                                     There are  condensations and rarefractions

                                  wavelenght : distance between the centers of two successive  

                                                            condensations /rarefractions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There is:

v = f . λ                    v speed of the wave  in m/s

                                   f frequency source in Hz

                                   λ wavelength  in m

 

Δ φ = Δ x/ λ           Δ x  distance between two points in a wave

                          Δ φ  phase difference between these two points       

                           λ and  Δ x : the same unit