EF151 Final Engineering Team Project: Austin Eldridge Armand Mendez Jack Huntley Erica Hawkins The Plexi-Trap

Design Overview  Ball Starts by rolling around ramp  Activates First Mouse trap which fires marble through tube  Marble hits Second Mouse trap which drops paper  Paper hits final trap that delivers the stamp

Equation Overview Gravitational Potential Energy  Kinetic Energy Conservation of Momentum Trajectory Equation Ball rolling down ramp ( slugs)(32.3ft/s/s)(.812ft) = ½ ( slugs)v^2 v = 7.23 ft/s Marble being fired from tube (0ft ft) = (1.08ft - 0 ft)tan(45°) - (32.3ft/s/s) / (2v^2) (1 + tan(45°)^2) (1.08ft - 0ft)^2 v = 5.53 ft/s Swing arm hitting marble ( slugs)(0 ft/s) + ( slugs)(v) = ( slugs)(5.53 ft/s) + ( slugs)(0 ft/s) v = 2.77 ft/s

Design/Construction Issues Mouse trap spring launched marble too far Needed longer mouse trap levers Reliability of projectile Original tubing for ball failed due to design constraints (height limit of box) and friction/air resistance Issue Solution Untwist spring to lower its k value Solder wire onto existing levers and extend them Practice makes perfect! Replaced tubing with wooden ramps

Conclusions  Infinite Number of ways to do something inefficiently  Still difficult to build something that works consistently  Friction and stored energy can do a lot more than you would think it should  Planning is key