Catapult

What is a catapult? A catapult is any kind of mechanical device that shoots or launches a projectile a great distance. The word 'Catapult' comes from the two Greek words "kata" (downward) and "pultos" (a small circular battle shield).

refers to the motion of an object projected into the air at an angle Projectile Motion Projectile motion refers to the motion of an object projected into the air at an angle

Projectiles In Motion

Projectiles In Motion

Catapult What are some key design goals when designing a catapult? What angle will you use to shoot your projectile? What will create a force to launch the projectile?

MATERIALS 3 - 20 cm long 6 - 10 cm long 2 - 10 cm long - the ends cut at 45o 4 - 5 cm - the ends cut at 45o Small nails 1 metal bar - 11 cm long 1 large rubber band 2 eye hooks Glue Gussets-made of balsa 1 metal cup for basket

Constructing the Side Support Using the 10 cm long pieces create 2 side supports that are mirror images of each other Use both glue and nails to create the sides. Add gussets for added strength

Now connect the two sides of the catapult together using the remaining four 10cm pieces. Use nails and glue Note: The upright wood pieces (the two vertical ones) are on the inside of the catapult base. Don't build it with these on the outside. It is stronger this way!

Swing Arm Assembly Drill a hole in the catapult arm about 2 cm from one end. This hole should just be a little bit bigger than the metal bar you are using. Now put a hook about 7.5 cm from the other end of the arm. Glue your metal cup to just above the hook

Add Catapult Arm to support Slide the bar through the side support then through the catapult arm then into the other side support. Add a bit of glue to bar and where it meets the side support to hold it firm

Add Elastic to Arm Put the other hook on the front of the catapult. The arrow shows where to put it. Then run a rubber band from that hook to the hook on the catapult arm. NOW IT’S READY TO FIRE - GET SOME MINI BLOCKS AND FIRE AWAY!