Marshmallow Catapult


Marshmallow Catapult

By Adventure Science Center

Making a catapult is a fun science activity

3… 2… 1… LAUNCH! Catapults were often used as weapons of war during the Middle Ages. Use this lesson to dive into motion, forces and energy with your scientist while building catapults out of everyday objects.


  1. Motion–
    (noun) an act or process of changing place or position.
  2. Energy–
    (noun) the capacity (as heat, light or running water) for doing work; power or ability to be active.
  3. Acceleration–
    (noun) the rate of change of velocity with respect to time; the act or process of moving faster.
  4. Force–
    (noun) strength or energy put forth; an influence (as a push or pull) that tends to produce a change in the speed or direction of motion of something.
  5. Speed–
    (noun) the act or state of moving swiftly; rate of motion.


  • Pictures of Catapults
  • Rubber Bands
  • Popsicle Sticks (9 per catapult)
  • Plastic Spoon
  • Marshmallows
  • Masking Tape
  • Objects of your choice to serve as targets


  1. Look through some pictures of catapults and discuss the elements that each has in common.
  2. Take seven of the popsicle sticks and tie a rubber band tightly around both ends so that all of the sticks are bound together.
  3. Take the remaining two popsicle sticks and tie a rubber band on one of the ends. Keep the band close to the edge of the sticks.
  4. Insert the seven sticks through the two-stick bundle. The closer the seven stick bundle gets to the edge, the more leverage the catapult will have.
  5. Tie a rubber band in a cross-fashion to join the two pieces.
  6. Use a few rubber bands to attach the plastic spoon on top of the two stick bundle.
  7. Mark a starting line using the masking tape. Place objects at various distances from starting line. Have your scientist place their catapult at the starting line, load it up with a marshmallow and let it fly!

Questions to consider:

  • What happens if you pull lightly on the catapult? What about if you pull harder?
  • What happens when you move the seven-stick bundle closer to the edge?
  • How did the catapult set the marshmallow in motion?
  • How could you improve the catapult design?




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