1. Quantitative presentation example: Does a paper ball and scotch tape pendulum behave like an ideal pendulum? Arnando Shastrini Minnesota State University Moorhead

2. Introduction Laws of pendulum motion first developed by Galileo In textbooks a pendulum is idealized as a point mass on a massless string L. In the absence of air resistance and for small angles Would a pendulum made of scotch tape and a wadded sheet of 8.5X11 inch paper follow this law? Would air resistance be substantial?

3. Experiment One sheet of 8.5X11 inch typing paper was crumpled into a loose ball approximately 2 inches in diameter. A piece of scotch tape 2 cm wide was attached to the paper ball. The tape was attached to a door frame. The distance L was changed, and the period T measured. L Tape Paper ball

4. Results

5. Discussion For an ideal pendulum, one expects the slope of T^2 versus L to be =4.0 s^2/m In this experiment, the slope was 4.1 s^2/m The relationship between L^2 and T seems to follow the behavior for an ideal pendulum in the range of L selected. The theoretical and experimental values are in good agreement, though formal error analysis was not performed.

6. Conclusions It appears that a pendulum made of a paper ball and scotch tape follows the behavior of an ideal pendulum very well within the range of pendulum lengths studied. Air resistance is expected to affect the longer periods more, because the longer length of tape is expected to cause more drag.