I found this physics engine online in which you can download tests. There`s only three to choose from but each one gives you scenarios to test out. There tiny downloads and there a great way to understanding how these engines work.

Meqon Engine (http://meqon.com/downloadarea/downloadarea.php)


It`s pretty fun, try it out.

Also, this Meqon engine is aparantly the new competition for the Havok reactor seen in games like Half Life 2.

Also. number 1 to 5 fire balls to knock things down. Hold right click and let go to make a blast in that area.

:)