Pendulum PeriodsA swinging pendulum keeps a very regular beat. It is so regular, in fact, that for many years thependulum was the heart of clocks used in astronomical measurements at the Greenwich Observa-tory.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 swing·the length of the pendulum, measured from the center of the pendulum bob to the point ofsupport·the mass of the pendulum bobTo investigate the pendulum, you need to do acontrolledexperiment; that is, you need to makemeasurements, changing only one variable at a time. Conducting controlled experiments is a ba-sic principle of scientific investigation.In this experiment, you will use a Photogate/Motion Detector capable of microsecond precisionto measure the period of one complete swing of a pendulum. By conducting a series of controlledexperiments with the pendulum, you can determine how each of these quantities affects the pe-riod.Figure 1OBJECTIVES·Measure 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.MATERIALSPower Macintosh or Windows PCStringUniversal Lab Interface2 ring stands and pendulum clampLoggerPromasses of 100g, 200g, 300g
Vernier Photogate or Motion Detectormeter stickProtractorGraphical Analysis or graph paperPROCEDURE1.