Physics I LabPendulum PeriodsINTRODUCTIONA swinging pendulum keeps a very regular beat. It is so regular, in fact, that for many yearsthe pendulum was the heart of clocks used in astronomical measurements at the GreenwichObservatory.There are at least three things you could change about a pendulum that might affect theperiod(the time for one complete cycle):the amplitude of the pendulum swingthe length of the pendulum, measured from the center of the pendulum bob to thepoint of supportthe mass of the pendulum bobTo investigate the pendulum, you need to do acontrolledexperiment; that is, you need tomake measurements, changing only one variable at a time. Conducting controlledexperiments is a basic principle of scientific investigation.In this experiment, you will use a Photogate to measure the period of one complete swingof a pendulum. By conducting a series of controlled experiments with the pendulum, youcan determine how each of these quantities affects the period.Figure 1OBJECTIVESMeasure the period of a pendulum as a function of amplitude.Measure the period of a pendulum as a function of length.Measure the period of a pendulum as a function of bob mass.
MATERIALSLabQuestVernier Photogateprotractorstring2 ring stands and pendulum clampmasses of 100 g, 200 g, and 300 gmeter stickPRELIMINARY QUESTIONS1.Make a pendulum by tying a 100 cm string to a mass. Hold the string in your hand andlet the mass swing.