In-class group activity 2

Use an on-line simulation from the University of Colorado PhET group to explore the behavior of waves on a string.  Link to the simulation: http://phet.colorado.edu/en/simulation/wave-on-a-string Click "Run Now!".

Investigate the behavior of a standing wave

• Start with the following settings:
  • Oscillate
  • No End
  • Amplitude: 20 (arb.   units)
  • Frequency: 50 (arb.   units
  • Damping: 5
  • Tension: high
  • Ruler and timer: checked
• Does this maximum amplitude change when you change the frequency slider?
• Change the end to a fixed end, the frequency to zero, and click the reset button.  
  • Slowly increase the frequency.
  • Can you find a resonance?  Are there multiple wave lengths you can find a resonance for?
  • What can you say about the wavelength associated with those frequencies?
  • At one of those frequencies, decrease the damping to zero and describe what happens.  

 If you wanted to figure out the tension in a cello string, how would you do it?

Write the equation for an arbitrary wave.