Curious Catapults

The catapult project is a creative and different way of displaying our knowledge of quadratic equations. Each team was to build a catapult that is capable of holding and shooting a table tennis ball in an arc. After the process of building, the shot of the catapult was filmed and put into Logger Pro, which gave a quadratic equation that roughly matches the arc of the table tennis ball. The purpose of this project is to solidify our understanding of quadratics and to know how quadratic equations can be applied to real-world situations.

My team (Angela and I) decided to use this catapult’s design. It is simple to build, while not requiring any wood cutting or complex structures.

One problem we had with this design was that the ball would not shoot upwards in an arc, but would shoot sideways. This caused the ball to be too low. To deal with this problem, a pencil was placed above the component that holds the ball when it is pulled back. With the pencil, the part of the catapult that launches the ball would stop before moving its maximum distance, making the ball fly at a higher angle.

I believe the hardest part of this project was evaluating whether the catapult’s design would be strong enough or if it needed modifications. Building and testing the catapult is not hard, but the planning and the modifying process may take a long time and/or be difficult because it involves a lot of trial and error.

My understanding of quadratic equations improved as I learned how quadratics are used in a real situation and how they can be used with different axes to represent different types of data (for example, height vs. time and height vs. distance are different and used in different contexts).

I believe the design process is important when doing a project like this, but the mathematical understanding of the catapults is the most important, especially in a math class. The unit of quadratics is possibly the most important of Algebra I, and there is no better way of showing understanding than in a real-life situation.

Catapult Video (download)