How to Make a Popsicle Stick Catapult

Build a simple popsicle stick catapult and explore force, motion, energy, and engineering at the same time! This easy STEM activity uses just a handful of supplies and can be adapted from elementary science through middle school.

Start by building the basic catapult, then test different projectiles, measure launch distances, or change one part of the design to turn it into a full science investigation.

Field: Physics & Engineering
Grades: 2–6+
Concepts: Force and motion, potential and kinetic energy, projectile motion, engineering design

How Does a Popsicle Stick Catapult Work?

A catapult is a simple machine that uses stored energy to launch an object. When you press down on the craft-stick arm, you bend the stick and store elastic potential energy.

When you release the arm, that stored energy changes into kinetic energy, or energy of motion. The arm moves quickly upward, transferring energy to the projectile and sending it through the air.

Once the projectile is launched, several forces affect its motion.

Gravity pulls the projectile toward Earth. Air resistance pushes against the projectile as it moves through the air. The angle, launch force, mass of the projectile, and catapult design can all affect how far the object travels.

Catapults are a great way to explore how energy transfers and forces work together.

👉 Learn more about potential and kinetic energy.

👉 Explore force and motion for kids.

Make It a Science Project

A basic catapult build can easily become a more complete science investigation.

The key is to change only one variable at a time while keeping the rest of your setup as consistent as possible.

• Projectile Mass and Launch Distance: Does the mass of the projectile affect how far it travels? Choose several objects with different masses. Launch each object three or more times and measure the distance.
• Catapult Position: Move the stack of craft sticks forward or backward between the launching arms. Does changing the position of the stack affect launch distance?
• Launch Arm Length: Experiment with a longer or shorter launching arm. How does the length of the arm affect the distance traveled?
• Projectile Shape: Compare objects with different shapes but similar sizes. Does shape affect how accurately or how far an object travels?
• Accuracy Challenge: Instead of launching for maximum distance, set up a target. Can you modify your catapult so that it launches an object accurately into the target?

Take the Catapult Challenge Further

This is one of those STEM projects that can grow with kids.

Have students:

• Identify the independent and dependent variables.
• Determine which variables need to stay controlled.
• Complete at least three trials for each test.
• Record quantitative data.
• Calculate averages.
• Create a graph or data table.
• Explain patterns in the results.
• Identify possible sources of error.
• Use evidence to support their conclusion.
• Modify the design and test it again.

👉 Look through our complete collection of Engineering Projects for Kids here

Think Like an Engineer

Give students a specific problem to solve. This was my son’s 6th-grade project challenge.

The challenge had specific distance and obstacle requirements, so we had to test, measure, and adjust the design until the catapult could meet them.

• Distance: 6 feet
• Obstacle height: 12-18 inches
• Projectile: ping-pong ball
• Goal: launch from behind a line, clear the obstacle, and land beyond the 6-foot mark

💡 Build a first design, test it, record the results, and then make one improvement. His first attempt failed, as did the second, but the third catapult was a success

👉 Make sure to incorporate the Engineering Design Process at this level!

The goal isn’t to create a perfect catapult on the first try. Engineers build, test, identify problems, and redesign. Not necessarily Pinterest-perfect — but exactly what engineering should look like.

More Catapult Designs to Try

Once you’ve built the basic popsicle stick catapult, try another design.

• LEGO Catapult: Build a working catapult with bricks and experiment with different structures.
• Marshmallow Catapult: Try a larger catapult design perfect for launching lightweight marshmallows.
• Pencil Catapult: Use common school supplies to make another simple launcher.

💡 You can also give your catapult a seasonal twist with candy pumpkins, jingle bells, hearts, plastic eggs, or other lightweight objects.

What Can Kids Learn From Building a Catapult?

A catapult combines science, technology, engineering, and math in one simple project.

Kids can explore:

• Force and motion
• Potential and kinetic energy
• Gravity
• Measurement
• Variables
• Data collection
• Engineering design
• Problem solving

The basic build is accessible for younger students, while older students can use the same catapult for much deeper experimentation and analysis.

Popsicle Stick Catapult FAQ

What age is a popsicle stick catapult good for?
The basic build works well for approximately grades 2–5, but it can easily be extended for 5th, 6th, and even middle-school students by adding variables, repeated trials, measurement, graphing, and design challenges.

What type of energy does a catapult use?
Pressing down on the launching arm stores elastic potential energy. When the arm is released, some of that energy changes into kinetic energy and launches the projectile.

How can I make the catapult launch farther?
Experiment with the position of the craft-stick stack, the length of the launching arm, the projectile, and how far the arm is pulled back. Change only one variable at a time if you want to compare results scientifically.

Is building a catapult science or engineering?
It’s both. Students explore physics concepts such as force, motion, and energy while also using the engineering design process to build, test, and improve their catapult.

His first design would not launch more than a foot on average. Of course, we took multiple test runs and wrote down the distances! His improvements launched the ball way off the table and more than 72″. Is it Pinterest-worthy? Not really. However, it’s the work of a junior engineer who solves a problem!