Catapults

Objectives

• Use ramps, pulleys, levers and pendulums.

Materials

• A lever arm (e.g. wooden ruler or jumbo popsicle stick)

• A round fulcrum (e.g. spool of thread or fat marker)

• Elastic bands

• Spoons

• Chalk or masking tape

• A load (e.g. pompoms)

Key Questions

• Can you get your pompom to the target/across the "water"?
• How can you change the distance the pompom travels?
• Where should the pivot point (fulcrum) be positioned to make the pompom travel the shortest distance?

What To Do

1. Assemble the catapults ahead of time for younger students.
2. Create “target zones” on the ground or a table using chalk or tape, based on your catapult’s range.
3. Demonstrate how to load and launch the catapults.
4. Encourage children to try them out.
5. Try adjusting the force you use with the catapults to fire the pompoms different distances into different zones (e.g. push gently to move the load a short distance, push hard for a longer distance.

Extensions

• For younger children, set up the fulcrums of several catapults, each in a different position.
• Which catapult flings the pompom farther?
• For older children, challenge them to adjust the location of the fulcrum themselves and see how it affects the distance the load travels.
• Hint: Set up the catapult with the fulcrum positioned so that it is least efficient at the start of the exploration to encourage children to adjust it.
• Theme the target zones, such as water with alligators or castles with guards. Add boxes or buckets to aim for.
• Competition – who can make their pompom travel the furthest?
• Have children design and decorate their own catapult.
• Learn about the history of the catapult and trebuchet.
• Explore teeter-totters and other levers in your neighbourhood.
• Build a giant catapult outdoors and launch water balloons or pumpkins.