Did you know that every year there’s a big competition for… launching pumpkins? It’s true! Last year, the pumpkin that was launched the farthest traveled almost a whole mile!

In the October Winkle Crate, we taught you how to make your own Pumpkin Chunkin Catapult. To see how it’s done, head to The Winkle YouTube channel for an instructional video that shows you step-by-step how to create a catapult.

A catapult uses potential energy to launch projectiles.

So what is a catapult? A catapult is an ancient weapon used to launch projectiles without the use of explosives.

A projectile is the object that is launched, such as a stone. In our Pumpkin Chunkin Catapult, the pumpkin is the projectile. The path the projectile takes through the air is called the trajectory.  The trajectory is affected by lots of things, like the size and weight of the projectile, for example.

Diagram showing how a catapult works, pointing out the catapult, projectile, and trajectory.

Catapults don’t use explosives to launch. That means you don’t need fire or gunpowder to use a catapult. Other kinds of launchers, like a cannon, need an explosion to send a cannonball flying through the air. Instead of an explosion, catapults use potential energy to launch projectiles.

There are two types of energy: potential energy and kinetic energy. Potential energy is the energy that an object has stored up and is ready to use, because of the position the object is in. Kinetic energy is the energy an object has because of how it is moving.

Imagine a boulder balancing on the edge of a cliff. Before the boulder falls, it has potential energy because it could fall. The potential energy builds up because of the position of the boulder. As soon as the boulder starts to move and fall, the boulder’s energy becomes kinetic.

Catapults are useful because they allow projectiles to be launched farther than a person could normally throw. It would be hard to throw a large stone at a castle wall, but a catapult makes it easy!

Pumpkin Chunkin Capapult, a fun engineering project for kids to learn STEM.

Try it yourself! Experiment with different projectiles in your catapult. Do lighter or heavier objects fly farther? What has the highest trajectory?

For more learning at home resources, check out The Winkle for STEM projects for kids and our blog for free homeschooling lessons, including Plants and Seeds and Pulleys and Simple Machines. Projects are available in The Winkle Crate, our amazing subscription service that makes learning STEM at home fun and easy for kids and parents.

Catapults and potential energy. A free online STEM lesson for kids about potential energy and a catapult STEM project for kids.