Labbage.

The purpose of today's lab is to determine mathematical relationships regarding harmonics on a string.  You will vary the frequency (number of string vibrations per second) and see exactly the wave forms change.

Brief procedure:

1.  Set up string and oscillator.  Record length of string from pulley to point where it is tied to oscillator.

2.  Find the lowest frequency that produces an n=1 harmonic ("one hump").  Record this frequency.

3.  Find the next series of frequencies that produce harmonics.  Record the harmonic number, frequency, and wavelength.  Repeat for several harmonics.

4.  Repeat the trials with a different weight on the end - this is effectively changing the tension in the string.

Calculations:

Determine the speed of the wave for each trial, using the expression:  speed = frequency x wavelength.  The speed values should be in the data table.

The data table should have:  harmonic number (n), frequency, wavelength, speed, mass.

Include a graph of frequency vs. harmonic number (for at least one of the runs).

In your conclusion, discuss the mathematical relationships you've found.  For example, how are frequency and harmonic number related?  How does tension affect the frequency?

Also include sources of error for this experiment.

Basic structure of the lab report:

Title

Purpose of lab

Data table

Sample calculation for speed (your data table will have ALL of the calculated values, but there is only need for one calculation to be shown)

Graph(s)

Conclusion - probably the biggest, most detailed part of the lab