Project Easy: Gauss Rifle

Description :

This science activity is very interesting and also teaches a lot of phenomenon of magnetism, conservation of energy and momentum.

Wooden Ruler
Sticky Tape
4 strong magnets(Any type but preferentially square or rectangular magnets)
9 steel balls with diameter that is close to match with that of height of magnet

Tape the first magnet to the ruler at the 2.5 inch mark. The distance is arbitrary. You can chose any distance. this is done to fit all the 4 magnets on the ruler.
Trim off the excess tape from the edges.
To the right of each magnet, place two steel balls. Arrange a target to the right of the device, so the ball does not roll down the street and get lost.
To fire the gauss rifle, set a steel ball in the groove to the left of the leftmost magnet. Let the ball go. If it is close enough to the magnet, it will start rolling by itself, and hit the magnet.
When the gauss rifle fires, it will happen too fast to see. The ball on the right will shoot away from the gun, and hit the target with considerable force. Our one foot long version is designed so the speed is not enough to hurt someone, and you can use your hand or foot as a target.

Take different size balls and place them such that first magnet has balls of maximum size and consequently reducing the ball size.
Number of magnets can be increased.
Strength of the magnets can be increased. Best results are obtained by using neodymium-iron-boron magnets which are quite expensive.