Physlet Illustration: The Speed of a Sound Wave

 

 
A sound wave travels inside a pipe as shown above. You see the (white) air molecules inside the pipe, and the bar graph show the pressure differential from atmospheric pressure. What is the wave speed?  How are the frequency and wavelength related to the wave speed?

Hints

  1. Measure the position of a crest at several times and determine the wave speed.  
  2. Pause the animation and measure the wavelength of the wave?
  3. Play the animation and measure the period and determine the frequency of the wave. 
  4. Can you calculate the wave speed from the wavelength and frequency?

Reference

See Walker, Section 14-1, 14-3, & 14-4

Illustration written by Chuck Niederriter