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Quantitative presentation example: Does a paper ball and scotch tape pendulum behave like an ideal pendulum?. Arnando Shastrini Minnesota State University Moorhead. Introduction. Laws of pendulum motion first developed by Galileo
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Quantitative presentation example: Does a paper ball and scotch tape pendulum behave like an ideal pendulum? ArnandoShastrini Minnesota State University Moorhead
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?
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
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.
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.