CUrious Magnets

Today our lab was on magnets and how to make a gauss rifle. You tape very powerful magnets to a ruler about 2 1/2 inches appart. Then you place 2 meatal ball bearings after each magnet. You then place a ball at one end of the ruler. The bal is pulled towards the magnet and thenthe energy is transfered from the ball to each other ball and magnet untill it comes to the end where the last ball shoots off the end.