Outdoor Survival Catapult

Outdoors CatapultBy: Ben Wynett and Garrett Lusk

PurposeOur objective was to build a catapult out of materials that you could typically find in the outdoors. MaterialsThick sticks for the base and thin sticks for the legsMasking tapeThread and yarnScissors LeavesRubber bands Small rockLife Saver gummyPing Pong ball

The Final Product

Side Note: The red rubber bands serve as the catapult, and the orange yarn provides stability. Rubber bandsYarn for stabilityDiagram

Basket for projectileOne of the four base structuresOne of four leg structuresThis is one of six joints. The joints are connected by yarn and masking tape. Launcher. What we pull back to launch projectileSample 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. ProcedureGather necessary materialsConstruct the base by using thread and tape Connect the legs to the base by using thread and tapeAttach yarn to all of the joints to increase the structurePlace the rubber bands on the legs to prepare for the launching motionPlace our projectile on the catapult, launch it, then collect the data to predict our total kinetic and potential energy produced by the Catapult. Data CollectionWe 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=1/2mv2Once 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 ItemLaunch DegreeRange of FlightTime of FlightMassVelocityKinetic EnergySmall Rock50 Degrees5.3 meters2.15 seconds.00107 kg2.46 m/s.017 JoulesLifeSaver Gummy50 Degrees2.3 meters1.61 seconds.000145 kg1.43 m/s9.2x10-4 JoulesPing Pong Ball50 Degrees2.03 meters1.52 seconds.00009 kg1.34 m/s8.1x10-5 JoulesLife SaverLaunch Angle: 50 degreesRange of Flight: 5.3 metersTime of Flight: 2.15 secondsMass: .000145 KE= .017 Joules

Small rockLaunch Angle: 50 degreesRange of Flight: 2.3 metersTime of Flight: 1.61 secondsMass: .00107 kgKE= 9.2x10-4 Joules

Ping Pong BallLaunch Angle: 50 degreesRange of Flight: 2.03 metersTime of Flight: 1.52 secondsMass: .00009 kgKE= 8.1x10-5 Joules

AnalysisOur 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 = mv2

Life SaverKE = (.00009)(2.52)2KE = 9.2x10-4 JoulesThe potential energy is equal to the kinetic energyPE = 9.2x10-4 JoulesSmall RockKE = (.00107)(1.43)2KE = .017 JoulesThe potential energy is equal to the kinetic energyPE = .017 Joules

Ping Pong BallKE = (.00009)(1.34)2KE = 8.1x10-5The potential energy is equal to the kinetic energyPE = 8.1x10-5ConclusionWe 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: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.The basket that we made for placing the object into kept falling apart, so we had to reconstruct our basket a few times.BibliographyThe only resource that we used was this YouTube videoBuilds, Josh. "How to Make an Easy Catapult." YouTube. N.p., 7 Oct. 2013. Web. 11 Dec. 2014.