(2) 
There are two weightless and solid bars with a mass at each lower end. The two bars are connected to each other, but they are free of rotation. Let's look at the motion of this double pendulum in a two dimensional plane. If we start the motion with just a small swing, we find that the motion has two normal modes.
If you download and run the program, the following picture will appear on the display. Let's change the display mode too.
For more information
click here,
Click the picture to magnify.
NijufrikoE.exe
