Crankshaft-Driven Pendulum

start/reset

randomize parameters

pendulum

length L

1.15

bob start speed θ'(0)

π

mass of bob m

1

damping coefficient μ

0.1

slider-crank drive

crank-rod length S

0.75

crank speed Ω

10

This Demonstration shows a special case of the damped and driven double pendulum. The pivot of the pendulum is driven up and down by a slider-crank mechanism. This transmits a vertical acceleration to the bob, in addition to the acceleration due to gravity. This results in the equation of motion

Lmθ''(t)+Lμθ'(t)+msinθ(t)[g+y''(t)]0

, where

y

is the vertical position of the pivot along the slider. The animation traces the movement of the pendulum bob.