Pendulum Formulas

Pendulums:

  • Florida gravity (30° latitude) = 32.1302

  • 4Pi² / 32.1302 = 1.2287

  • 1 / 1.2287 = .8138

  • A 2-second period (tick-tock) pendulum in Florida has a length of 39.065" (3.255').

  • These formulas actually apply to a pendulum with an infinitely small swing, but they give a reasonable approximation if the angle isn't too large!


  • Find Period when given Length
    Time = SQRT ((4Pi² * Feet) / Gravity)
    Time = SQRT (Feet * 1.2287)
    Time = SQRT (Feet / .8138)
    2 seconds = SQRT (3.255 * 1.2287)
    2 seconds = SQRT (3.255 / .8138)


  • Find Length when given Period
    Length (feet) = Time² * (Gravity/4Pi²)
    Length (feet) = Time² * .8138
    3.255 feet = 2² * .8138


Comments about this page and links are welcomed.
Send them to: dbrown28@tampabay.rr.com