Things You'll Need
Instructions
Place one straw next to another straw, so that they are in line. Grasp a piece of masking tape and slide it around the center of the straws to tape them together. Repeat this process to create six additional straw pairs.
Set three of the straw pairs on a table, in the shape of a triangle. The edges of the straws should overlap slightly. Tie the sides of the straws together using one rubber band for each connection. If the rubber band fails to keep the straws in place, add masking tape.
Attach a straw pair to one of the triangle corners using a rubber band or masking tape. Repeat the process for the remaining two corners and join the straws in a point using a rubber band. The figure should look like a triangle.
Create a paper cup for the catapult. Draw the shape on graph paper consisting of a three square tall and two square wide rectangle, with one extra square on the middle of the left and right of the rectangle, for a shape that looks like a cross. Add a tail to the bottom-right of the shape, that is about five squares long. Fold this shape into a paper square and secure it using tape.
Tape the cup to the edge of a straw using masking tape.
Punch a hole through the edge of the straw opposite the cup. Cut a rubber band and slide it through the hole.
Slide the rubber band around the point of the triangle and tie knot. The knot should be tight but it should still allow the straw arm to move.
Test the catapult by placing a small object in the paper cup, pulling the cup backwards and releasing it. If the object flies through the air, the catapult is working.