Outdoors Catapult By: Ben Wynett and Garrett Lusk Purpose Our objective was to build a catapult out of materials that you could typically find in the outdoors. Materials Thick sticks for the base and thin sticks for the legs Masking tape Thread and yarn Scissors Leaves Rubber bands Small rock Life Saver gummy Ping Pong ball Yarn for stability The Final Product Side Note: The red rubber bands serve as the catapult, and the orange yarn provides stability. Rubber bands Diagram This is one of six joints. The joints are connected by yarn and masking tape. One of the four base structures Basket for projectile One of four leg structures Launcher. What we pull back to launch projectile Sample Launch Video This was not one of our best launches, in fact it was one of the first, but this can allow you a look into the basic mechanics of how it works. Procedure 1. Gather necessary materials 2. Construct the base by using thread and tape 3. Connect the legs to the base by using thread and tape 4. Attach yarn to all of the joints to increase the structure 5. Place the rubber bands on the legs to prepare for the launching motion 6. Place our projectile on the catapult, launch it, then collect the data to predict our total kinetic and potential energy produced by the Catapult. Data Collection We launched 3 different objects: life saver, small rock, and a ping pong ball. With these data, we will find the Kinetic and Potential energy using the equation: KE=1/2mv2 Once we find the Kinetic Energy, we know that the Kinetic energy is equal to the Potential Energy, so once we know one we know the other. Data Item Launch Degree Range of Flight Small Rock 50 Degrees LifeSaver Gummy 50 Degrees Ping Pong 50 Ball Degrees Time of Flight Mass Velocity Kinetic Energy 5.3 meters 2.15 seconds .00107 kg 2.46 m/s .017 Joules 2.3 meters 1.61 seconds .000145 kg 1.43 m/s 9.2x10-4 2.03 meters .00009 kg 1.34 m/s 1.52 seconds Joules 8.1x10-5 Joules Life Saver Launch Angle: 50 degrees Range of Flight: 5.3 meters Time of Flight: 2.15 seconds Mass: .000145 KE= .017 Joules Small rock Launch Angle: 50 degrees Range of Flight: 2.3 meters Time of Flight: 1.61 seconds Mass: .00107 kg KE= 9.2x10-4 Joules Ping Pong Ball Launch Angle: 50 degrees Range of Flight: 2.03 meters Time of Flight: 1.52 seconds Mass: .00009 kg KE= 8.1x10-5 Joules Analysis Our objective was to figure out what the kinetic and potential energy would be if we launched 3 different objects: life saver gummy, small rock, and ping pong ball. We used the equation: KE = ½ mv2 Life Saver KE = ½ (.00009)(2.52)2 KE = 9.2x10-4 Joules The potential energy is equal to the kinetic energy PE = 9.2x10-4 Joules Small Rock KE = ½ (.00107)(1.43)2 KE = .017 Joules The potential energy is equal to the kinetic energy PE = .017 Joules Ping Pong Ball KE = ½ (.00009)(1.34)2 KE = 8.1x10-5 The potential energy is equal to the kinetic energy PE = 8.1x10-5 Conclusion We ultimately figured out how to make our catapult, and we were satisfied with our progress. We faced many problems while we were working on our project: 1. We struggled with using materials out of the woods, so we had to resort to materials such as yarn and tape to connect the different parts together. 2. The basket that we made for placing the object into kept falling apart, so we had to reconstruct our basket a few times. Bibliography The only resource that we used was this YouTube video Builds, Josh. "How to Make an Easy Catapult." YouTube. N.p., 7 Oct. 2013. Web. 11 Dec. 2014.