# Physics 312, Extra Credit for Week #3: due Apr 1, 1998, at 5 PM

How does the period of a pendulum depend on its length?

This project may be done by teams of 1-2 individuals. You must design a device which can be used as a pendulum; the device must be adjustable so that its overall length can be varied by at least a factor of two. The device must be hung from the same point of attachment each time, and must have very little material above the point of attachment. A single meterstick with a number of holes in it is not a good device for this project. Draw a picture or two of your device, showing it at its maximum and minimum lengths.

Measure the period of your pendulum when it is set to 4 or 5 different lengths. Make sure that you swing the pendulum through a small angle, no more than 15 degrees from the vertical. Make two measurements of the period at each length, to check for one-time errors.

Draw a graph which shows the period of the pendulum on the Y-axis, and the length of the pendulum on the X-axis. Plot all your data. Write the formula for period of a pendulum as a function of its length. Draw a curve on your graph which exhibits this expected, theoretical behavior. Does your pendulum exhibit this behavior? If it doesn't, explain why not.

Submit a report which contains the pictures and descriptions of your experiment, as well as the results. You may also include interesting items you discovered during the course of the procedure.