Logo

The Lab

The Lecture Room

The Undamped and Undriven Pendulum

Damped and Driven Pendula

Pendulum Driven by a Periodic Force

Horizontally Driven Pendulum

Vertically Driven Pendulum

Pendulum With Rotating Suspension Point

The Vertically Driven Pendulum

acceleration of gravity = 9.81 m/sec2
Either your Web browser isn't able to run Java applets or you have forgotten to switch on this feature.

For instructions click on here.
For the equation of motion click on here

Suggestions for EXPERIMENTS
  1. Choose length = 1 m, damping = 0.1 sec-1, and amplitude = 0.07 m. Start with an initial condition of roughly 10° and observe the behavior for different values of the frequency between 0.2 Hz to 1.2 Hz. In most cases, the initial oscillation dies out except for values around 1 Hz where the down-hanging equilibrium is no longer stable. Note, that the frequency of the excited oscillation is half the frequency of driving.
    Related topics in the lecture room: Parametric resonance.
  2. Choose length = 1 m, damping = 0.1 sec-1, amplitude = 0.07 m, and frequency = 0.8 Hz. Depending on the initial condition, you will get either a strong oscillation or the oscillations decay to zero.
    Related topics in the lecture room: Parametrically excited oscillations.
  3. Choose length = 1 m, amplitude = 0.3 m, frequency = 3 Hz, and arbitray nonzero damping. Start with an intial condition near 180°. You will find that the upside-down pendulum is no longer unstable. Why?
    Related topics in the lecture room: The upside-down pendulum.

arrow

arrow

arrow

previous

top

next


© 1998 Franz-Josef Elmer,  elmer@ubaclu.unibas.ch last modified Saturday, July 25, 1998.