Here you will find simulation examples of a different study and engineering problems. The problems with all necessary math formulas are described in the articles. In the end of the article sometimes you can find link to a session file (simple text file), which can be executed in DYsolve application. So, you will have ready to use interactive calculation document. DYsolve application can be found in "tools".
The thematics is spontaneous. However, basically it is related to the mechanics of the rigid bodies. You can send us your ideas for the simulations.