A and E block lab prep

During our next class, you will collect data for the new "harmonics on a string" lab.  Here is what to expect:

Procedure:

1.  Assemble harmonics apparatus:  sine wave generator, oscillator, string, pulley, weight to hang over end.

2.  Record L, the distance from oscillator (metal tip that vibrates) to top of pulley.  Keep this fixed during the experiment.

3.  Starting from a frequency of 1 Hz, raise the sine wave generator until a clear n=1 harmonic is formed.  You may find that the frequency is not an integer number.  Record the frequency for the clearest harmonic you and your partner(s) can find.  Repeat this for the next several harmonics, as many as you can see.  Use a strobe light if helpful.

4.  In a table, record the following (though not necessarily in this order):  m (kg), W (N), L (m), n, f (Hz), wavelength (m), and v (m/s).

5.  Calculate the relevant weights, wavelengths, and speeds for all trials.

6.  Try a different hanging mass and repeat the experiment.  If you have time, do additional hanging masses.

Analysis

You have data and calculations.  What can you see (and say) about these relationships?  You'll need to write about each relationship, and supply a graph (if helpful to make your case).

- harmonic number and frequency
- speed and frequency
- speed and tension (supplied by the hanging weight)*

* You may need to obtain data from other groups, particularly if you are generating a graph here.

What things can you conclude about waves on a string?  Are these ideas applicable to sound waves in air?

This lab write-up will be due in 3-4 classes after you perform the experiment.