This applet illustrates the simple plane pendulum, with or without damping.
The user enters the damping coefficient and initial conditions, and the applet animates the
pendulum's motion and plots the angular velocity versus the angle.
Such a plot is called a phase portrait.
In this applet, the damping coefficient is measured in units of the critical damping for small oscillations. The energy
is chosen to be zero when the pendulum is hanging straight down at rest, and the pendulum has one
unit of energy when it is at rest at an angle of 90 degrees.
Instructions for use
- Using the scrollbar provided, enter the damping coefficient.
- Enter the initial angle and angular velocity by single-clicking with
the mouse at the desired location in the phase plane. This also starts the animation.
- Stop the animation by clicking "stop".
- Repeat as often as desired. To clear the screen, click "clear".