The Catapult Contest

A notice arrived in the staffroom on Monday morning. It said: Catapult Contest — Friday. Identical kit for every team. Score = median of three throws, not the best. Standing record: 4.6 metres. The rules stopped three teams before they started. Median of three — not best of three. The machine that throws wildly, that launches four metres one throw and two metres the next, will score two metres. The only machine that wins is a machine that throws the same distance every single time. That is not how most students think about a catapult. They think: pull back harder. They think: longer arm. They think: more rubber bands. None of that gives you a consistent machine. Consistent machines come from understanding what is happening — exactly — between the moment you let go and the moment the projectile lands. The energy starts in your muscles. It moves into the rubber band when you stretch it. It transfers to the arm when you release. It moves into the projectile at launch. It travels as motion until gravity wins. Every part of that chain has a variable you can tune. Pull-back depth. Pivot position. Band thickness. Release angle. Each one changes the throw — and changes it in a way you can predict, test, and set. Today, your team is going to build, tune, and certify one.