Pendulum Lab is an interactive physics simulation written in Java. It can be run on Windows, Mac OS X, Linux and any Java-capable web browser, which makes it extremely portable. The simulation deals with quite a few different topics. Some of those are gravity, mass, periodic motion, friction, velocity, and acceleration.
The simulation is quite simple. There is a pendulum on the screen, and you can click on it and move it. When you drop it, the pendulum will start swinging. You can then change the length of the string holding the pendulum bob and its mass. You will soon realize that these factors influence the motion of the pendulum. It gets interesting when you add friction to the pendulum. This effectively slows down the pendulum. On the other hand, you can also play with the force of gravity. The available options are Moon, Earth, Jupiter, Planet X and 0 gravity. In 0 gravity, the pendulum will probably keep on moving forever.
From the settings pane, you can choose to see the simulation in real time or in slow motion (1/4 or 1/16).
Pendulum Lab is a nice and illustrative simulation. However, I found that after a while, one of the pendulums would suddenly stop moving. This is a bug, and not the effect of any of the available variables.
