Catapult's

Materials

• Popsicle sticks (8)

• Rubber bands (at least 5)

• Glue

• Plastic bottle cap to hold a cotton ball

• Cotton ball (If you do not have any available, you can make a small ball by crumbling some paper.)

• Small open area (One square meter will do. It should be a sturdy, flat surface such as a table or floor.)

• Optional: markers to decorate your popsicle sticks

  
  

• Prep Work

• Note: The simple catapult described in this project is safe when used with a cotton ball. Shooting hard objects or using other homemade catapults can be dangerous. Make sure any objects you launch are soft and light so as not to harm anyone or cause any damage to objects around you.

• Optional: use markers to decorate your popsicle sticks before you start.

• Take six craft sticks, stack them one on top of the other. Secure these sticks together by wrapping rubber bands around both ends of the stack. You will anchor the launching stick to this stack, as described in the next step.

  
  

  Image Credit: Ben Finio, Science Buddies / Science Buddies

• To add the launching stick take one stick and attach it perpendicular to the stack you just made, around the middle, so you get a cross shape. You can do this with one or two rubber bands that are crossed in an X over the sticks. If you cross it this way, the sticks will stay nicely perpendicular.

  
  

  Image Credit: Ben Finio, Science Buddies / Science Buddies

• Next, add the base by attaching a stick to one end of the launching stick with a rubber band. If it were not for the stack of sticks in between, the launching stick would fall flat on top of the base. Now the launching stick and the base form a V shape lying on its side with the stack of sticks in the middle.

  
  

  Image Credit: Ben Finio, Science Buddies / Science Buddies

• Put your catapult on its base, locate the end of the launching stick that sticks up and glue the bottle cap there so it forms a small cup to hold the cotton ball.

  
  

  Image Credit: Ben Finio, Science Buddies / Science Buddies

• Wait until the glue is dry.

Instructions

1. Put your catapult in an open area with a sturdy, flat surface such as a table or an open space on a hard floor. Clear about a meter of open space for the cotton ball to fly and land.

2. Place a cotton ball in the launching cup, push the cup down just a little bit and let go.

   What happened to the ball? Did it fly? Did it go high or low? Where did it land?

   What do you expect will happen when you push the cup farther down? Will this make it fly higher, farther, both higher and farther or take the same path but maybe faster?