Pendulum Experiment - The Galileo Theory 

   The pendulum experiment was designed by Galileo Galilei.  He devised this experiment because he was trying to get a better understanding of the study of motion.  Galileo began to study motion and other aspects of time in the early 1600s.  

    He was first inspired by the study of motion when he noticed a peculiar thing at a church.  He noticed a chandelier hanging from a church ceiling and decided to time it.  He timed it with his pulse.  Eventually, he came to a few conclusions about pendulums and time having to deal with pendulum movement.  

    Galileo observed that the bobs of pendulums nearly return to their release height. Today this fact demonstrates conservation of energy, a principle not yet discovered in Galileo's time. As a recreation, pendulums were released from different heights. The height the pendulum returned to was noted and compared to the release height. The pendulums don't exactly return to their release height, and after each swing, it takes less and less time for each swing to complete a full cycle.  We (our class) observed this in our experiment.  Note that the change in time in very minor, almost unnoticeable. In our experiment, it was the incline that affected the time it took for the pinball to roll down to the end of the metal groove.

    Galileo noted that lighter pendulums come to rest faster than heavier ones do. As a test of this observation, two pendulums, nearly identical except for their bobs of different weights, were released at the same time and height. A bob of lead was hung with a string length of almost 30 centimeters. A bob of cork was hung to hang at 29.0 cm. The two were released at the same time after being pulled back about 5 degrees. After waiting for several minutes, the cork bob came to rest while the lead bob was still moving, which proved Galileo's hypothesis correct.

    Galileo found that the period squared is proportional to the length for a pendulum. As a test, lead pendulums differing in length by factors of two and four were compared. Pendulums of lengths 24.0 cm and 50.5 cm were released simultaneously. The shorter pendulum was allowed to pass through 28 cycles as the oscillations of the longer one were counted. The data is below.

24.0 cm string 28.0 28.0 28.0 28.0 28.0
50.5 cm string 20.0 19.9 19.8 20.0 19.9

Here are the results from our Experiments : Class Results

By Yash Patel