Mousetrap Catapult

There are many components to making a successful catapult. This is how I made mine: 

First I started with the simple mousetrap. I took off all the parts except for the spring. The first thing that must be built is the head, which the ball will sit in and be launched from.

 As you can see above, I made the head out of an egg carton so it would fit well.

 Next, I placed a block of wood on the mousetrap to stop the arm from swinging all the way. This will help later when the catapult is assembled.

  I built a base about ½ a foot tall out of legos. The reason for this is because the higher off the ground, the more time it will stay in the air, the more distance it will cover.

 Then I mounted the mousetrap on a 45^o angle to the base. 45^o will maximize the distance: it has just the perfect balance of horizontal and vertical distance. The arm hits the wood at 45^o a foot above the ground, maximizing the distance covered.