What you will need:
- Six large craft sticks
- One Popsicle stick
- Binder clip (approx. 1 ¼ “ wide)
- Bottle cap
- 6” string
- Hot melt glue gun
- Sharp knife (adult use only)
- Ruler or tape measure
- Mini marshmallows or some type of SAFE ammunition to launch
- Adult supervision
Procedure:
- Cut two small notches into four of your craft sticks (A) as shown
- Cut two small notches into one of your craft sticks (B) as shown
- Using your hot melt glue gun, glue one of your craft sticks to one of the wires as shown
- Place craft stick (B) over craft stick (A) making sure that the notches line up and carefully glue them together using your hot melt glue gun.
- Place craft stick (A) over craft sticks and wire making sure that the notches line up and carefully glue them together using your hot melt glue gun.
- Turn your catapult over and glue craft stick (A) to wire as shown (just like you did previously on the other side)
- Glue a regular size Popsicle stick on to craft stick (A) as shown
- Glue your last craft stick (A) over the top of the Popsicle stick making sure to line up the notches as shown
- Glue another Popsicle stick at a 90 degree angle as shown. This will provide stability to your catapult.
- Turn your catapult upright and attach a bottle cap as shown
- Tie a string around the notches in the bottom craft stick. Now tie the other end of the string around the notches in the top craft stick. This string should keep your catapult from opening more than about a 45 degree angle. Adjusting this string will change your trajectory, or the angle that your load will be fired.
- Place one hand over the base craft stick while pressing down on the end of the top Popsicle stick. Now, place a mini marshmallow in the bottle cap, aim and LET IT GO!
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What is going on?
Catapults are designed to launch projectiles great distances without the use of explosives devices! Binder clips are made to remain in “closed” when at rest. Pressing on the wires that are attached to the sides of the clip allows you to open the clip but as soon as you release it, the the tension causes the metal clip to spring back into a closed position with quite a bit of force.By adding the craft sticks, we can use the energy of this binder clip to propel a marshmallow quite some distance.
Try this:
Try adjusting the length of the string to change the flight path of the marshmallow. How far can you launch it?
Radical Rick
Extreme Science
509-892-7621
