By: Nahdir Austin Honors Physics Period 2

 First used in the Han dynasty’s seismometer device by scientists Zhang Heng.  Tenth century Egyptian astronomer Ibn Yunis used a pendulum for time measurement.  Leonardo da Vinci made many drawings of the motion of pendulums.  Italian scientist Galileo Galilei was the first to study the properties of pendulums, beginning around  Most accurate time keeping device up until the 1930’s, when the quartz was invented.

 A pendulum is a weight suspended from its pivot so it can move freely.  When released the restoring force combined with the pendulum's mass causes it to oscillate about the equilibrium position, swinging back and forth  Period: Time for one complete cycle, a left and right swing.  Swing periods of a simple gravity pendulum is dependent on its length, acceleration of gravity, and its amplitude.  The property of isochronisms is the reason why pendulums are good for timekeeping.  Isochronisms: regardless of the amplitude of oscillation the period of pendulums of equal length is constant.  They are directly effected by the acceleration of gravity, which is constant.  Since the force of gravity slightly differs throughout the earth, pendulums need to be adjusted when moved to a new area.

 Used as a gravimeter to measure local gravity.  Used in seismometers, which measures earth’s tremors.  They are an important factor for Schuler tuning, which is used in guidance systems of planes and ships  Some religions use pendulum motion at religious ceremonies such as The swinging incense burner called a censer.