H
Chapter 16/17 - Waves
  
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  Propagation of a Disturbance              
                                     
      • all mechanical waves require (1) some source of disturbance, (2) a medium that can be disturbed, and (3) some physical mechanism through which elements of the medium can influence each other.

• energy is transferred over a distance, but matter is not.

• electromagnetic waves do not require a medium to propagate.		      
   
Longitudinal
    A traveling wave or pulse that causes the elements of the disturbed medium to move parallel to the direction of propagation is called a longitudinal wave.          
                   
                 
              A traveling wave or pulse that causes the elements of the disturbed medium to move perpendicular to the direction of propagation is called a transverse wave.      
      Transverse        
                               
                                     
                       
      Earthquake seismic waves are three-dimensional waves that radiate out from a point underneath the surface of the earth. Both longitudinal (p-waves) and transverse
(s-waves) waves are generated.		      
                       
 
  y(x,t) = f(x - vt)
 
y(x,t) = f(x + vt)
   
 

 
A derivation for you. . .    
               
                           
               
  Derivation of
      Velocity on a String
               
                           
                 
Energy Transfer

Waves transport energy when they propagate thru a medium