I am SO excited to share these pumpkin catapults with you!! I was trying to think of a new, hands-on Halloween science project for our Halloween Science in the Park day while I was cleaning when my eyes landed on a Fall display we have with lots of little mini-pumpkins. I stared at them for a few minutes, trying to imagine any kind of STEM activity we could adapt to include pumpkins. And then it hit me: a Pumpkin Catapult science experiment!

And not just pumpkins flying in the catapult, but using the actual pumpkin as a base for the catapult! Not only did it tie into the pumpkins, Halloween, Fall, and science themes, the pumpkin created a base for a catapult that was sturdy and simple enough that older preschoolers could build their own catapult! The grooves on the pumpkins helped stabilize the rubber bands, which in turn made this project perfect for little hands!

Halloween Science

Pumpkin Catapults:

Our pumpkin catapults only needed four items: mini pumpkins, spoons, rubber bands, and a fulcrum. We tried everything from sticks to make-up for the fulcrum, but finally settled on bringing craft sticks for everyone so that each child could easily adjust the size and position of their own fulcrum.

The pumpkin catapults have three main parts: the pumpkin base, the spoon spring arm, and the craft stick fulcrum. The rubber bands hold everything together. You can move the parts around and secure them with varying amounts of tension to get very different results in your catapult!

I showed the everyone a pumpkin catapult we had made in advance, and let them try launching a pompom a few times. Then we put out the supplies and everyone got busy! My oldest kids started figuring out their own catapults right away. For the kids that needed instructions, I told them them to use the rubber bands to secure the spoon first, and then find a place for the craft sticks (fulcrum). They would need to experiment a little to find the spot that gave them the most spring in their spoon. They could add as many rubber bands as they wanted to get the tension they thought was best. It does NOT need to be done in this order, but it was an order that worked for some kiddos that needed more guidance.

A lot of the kids tested it with the pompom I brought, but then they spread out into the park to find their own payloads to launch. One of the best things we saw were acorn caps...one little girl launched her acorn cap near the top of a 20 or 30 foot tall pine tree!

Our younger preschoolers all needed a lot of help building it, but were able to use them independently. Most kids 5 and over could build a pumpkin catapult by themselves. Older kids (of all ages!) had a great time doing the entire project by themselves, and could apply a lot of physics principles to the size and position of the fulcrum; the type, number, and position of rubber bands; and the payload (or actual object that gets launched). Actually, we had some fantastic conversations with kinder kiddos about choosing a payload, and how its weight and size affect how far it will go!

I love how many science concepts and skills this one project integrates. It requires science processing skills like observing, planning, creating a hypothesis, experimenting and testing your plan, analyzing your results and making any changes needed. As they experiment, they experience first hand physics concepts of levers/cantilevers, fulcrums, payload, energy, gravity, force, mass, and more!

You could also put the supplies needed in a "suprise STEM bag" and challenge your kids to create a catapult with the supplies in the bag. This easily covers all four STEM areas at once:

SCIENCE: science process skills

TECHNOLOGY: you're creating a piece of technology! You could also let them take pictures of it, measure how far their launches go, or make a movie of the process!

ENGINEERING: building a catapult, levers/cantilevers

MATH: qualitative math about fulcrums, energy, force, and levers. If you're working with high schoolers or junior high studets, you could have them calculate the mechanical advantage of the lever and ask how a spring-y plastic spoon affects that ratio. You could also provide a scale to weigh the payload (also TECH)!

Our kids were also quite pleased with their pumpkin catapults in an artistic way...they loved how they looked! You could provide a little paint or stickers for decorating, and create a STEAM project too! (science, tech, engineering, art, math)

Our kids had so much fun building and launching these that I think we will keep them out for a couple weeks--after all, pumpkins can fit Fall, November, and Thanksgiving themes too! This pumpkin catapult science experiment may even become a new pumpkin tradition for us!

Have you ever done a Halloween Science in the Park Day? I should write up more about how we've done it, but until then, you may enjoy our Halloween Science Projects and Activities:

Are you looking for more Halloween Science Experiments? Check out our collection!! We love combining Halloween and science, and these are our favorites experiments and activities!

Do you love pumpkin STEM projects? My friend and fellow science-teacher-turned-mom-blogger, Sarah, has a great article about how you can turn pumpkin carving into another great pumpkin STEM activity too! I bet you'll love it!

Happy Educating,

Carla