Physion is a 2d simulation physics tool. It may be used for educational purposes in comprehensive and even high school at physics lessons.
A teacher can make a physics lesson an unforgettable experience for students and both teach and entertain at the same time by making them interested in the subject. The program has a plenty of good video tutorials on its website that give lots of ideas about what you can do with this tool.
The matter is that the program shows some physical properties of the objects in their process. There are a plenty of different scenes included into the program: you can observe such processes as zero friction, the person falling down the stairs, the objects explode etc. The teacher can demonstrate a catapult, a gear, segway, tank and other mechanisms in action.
The program may also come in handy in teaching the movements of heavenly bodies and satellites.
You can add various geometrical objects to the scenes you choose and edit their properties. There are lots of them: squares, circles, wheels, chains, ropes, gears and others. If you wish you have a possibility, for example, to make a car crash test by adding any objects on the way in front of the automobile with a driver and watch the path of motion both the driver and the car.
After all, the software can surely serve a purely entertaining purpose and provide you lots of fun.