Organ Pipes and Standing Waves

http://www.physics.smu.edu/~olness/www/05fall1320/applet/pipe-waves.html

Play with the applet above, observing the wave with the tube open on both ends.  Then try one end open only.

Increase the number of harmonics and note how the wave shape changes.

This is important - the air molecules move as depicted in the animation on top.  The animation below represents graphs of air molecule motion (displacement) or pressure (if you click on that button).

Try these problems (E block, for Tuesday.  A block can hold off on trying these until after Monday's class.)

1.  A tube is open on both ends (as shown in class).  Assume that the speed of sound is 340 m/s.  The tube length is 0.5-m.  Find the following:

a.  the wavelength of the n=1 harmonic (lowest harmonic that fits in the tube)
b.  the frequency of this harmonic
c.  the frequency of the next 2 harmonics above n=1.  Assume that it basically works like a guitar string.

2.  If you wish a tube to vibrate at concert A (440 Hz), how long should it be?

That's it.  Sorry again (E block) that we started late today.