Our challenge was to create a catapult out of a simple mouse trap. First, I attached a spoon with duct tape onto the arm of the mouse trap. This would be the catapult's arm, what will fling it into the air. When I tested it, the ping pong ball went straight up and did not travel a great distance. I had to experiment and change things on my original design. I began with the arm, looking for ways to improve it. I tried a variety of different size spoons, but it did not seem to matter as much. So instead, I looked at the shape of the spoon, and saw that the spoon's cup was bent so that it would just fly straight up. So, with the help of my dad, I heated up the plastic spoon and molded it so that the cup was curved. This would send the ball in the right direction.
Next, I thought back to the things we were learning in class. I remembered talking about speed and velocity. I remembered that there was a vertical velocity and a horizontal velocity. What I needed to aim to do was not let there be too much vertical velocity, or too much horizontal velocity. So I pictured a graph, and a 90 degree angle. I would want the path of the ball to be right in the middle, exactly half of 90 degrees. This way, the horizontal and vertical (x and y) would be equal. So, I drilled a nail on an angle to make the spoon stop at about a 45 degree angle.
This improved the distance an extremely large amount. I then tried to see if tilting the catapult itself would help at all. So I put the front of it up on a platform and tried different heights to see if any could improve the distance. When I rose the front 2.3 inches, it made the greatest positive impact on the distance.
This was what my final design looked like:
This was what my final design looked like: