EF 151 Rube-Goldberg Device

Team Members  Daniel Triplett  Scott Wherry  Devin Adams  Jonathan Brickey

Materials  Dominos  PVC Piping  1 Foosball  1 Golf Ball  Duct Tape  Electrical Tape  Glue  2x2 sheet of plywood  Shims  Light Switch  Yellow Light  1 Battery

Overview  Ball starts down ramp.  Ball falls through PVC piping and hits dominos.  Dominos fall and hit golf ball on ramp.  Golf ball rolls down ramp and lands in bottle.  Bottle + golf ball go over edge of table.  Weight of bottle + ball flip switch tied to bottle.  Light turns on.

Demonstration

Types of Energy Conversions  Given:  Mass (orange ball) =.005 kg  Mass (golf ball) =.01 kg  Mass (dominoes) =.002 kg  Height of First Ramp =.833 feet  Height of Second Ramp =.0833 feet

Energy Conversions  Part 1:  The orange ball rolls down the ramp, into the pipe, and out onto the platform.  Calculations: Finding the velocity as the ball exits the pipe. The point where the ball exits the pipe is set as the datum.  Conservation of Energy  mgho =.5mv2 (masses cancel out)  (32.2)(.833) =.5v2  v = 7.32 ft/sec

Energy Conversions  Part 2:  The orange ball collides with the first domino as it exits the pipe.  Calculations: Finding the velocity of the domino upon impact of the orange ball, traveling with a velocity of 5.18 ft/sec.  Conservation of Momentum  m1v1 = m2v2’  (.005)(7.32) = (.002)v2’  v = 18.3 ft/sec

Energy Conversions  Part 3:  The dominoes complete their chain reaction-rally and collide with the golf ball place on the top of the second, smaller ramp.  Assumptions: The dominoes maintain a constant velocity throughout their rally.  Calculations: Find the velocity of the golf ball following its collision with the domino.  Conservation of Momentum  m1v1 = m2v2’  (.002)(18.3) = (.01)v2’  v = 3.66 ft/sec

Energy Conversions  Part 4:  The golf ball rolls down the ramp into the bottle.  Calculations: Finding the velocity of the golf ball as it drops into the cup, in turn, flipping the switch.  Conservation of Energy  mgho +.5mvo2 =.5mvf2 (masses cancel out)  (32.2)(.0833) +.5(3.66)2 =.5vf2  vf =.895 ft/sec

Conclusions  The project is success in that it performs the function we had in mind. The ball drops from its initial height, hits the dominoes, which in turn hits a ball that will cause the lighting of a bulb.  What we learned was that these projects require proper planning, and that you cannot just leap right into it. I think maybe a better outline/sketch would have been more beneficial and could have saved more time. This knowledge can help in future courses and projects.  Also, this project helped us better understand the different types of energy conservations and how they play out in the real world.  Once we got everything down, we really had only a few problems. The only real problem was that at first the ball did not drop the bottle off the table, which in turn did not light the bulb. This was fixed by creating an easier resting point for the bottle so when the ball landed in the bottle, it dropped with greater ease. And the only other problem was the setting up of the dominoes. The dominoes can fall easily, so when setting up we had to be very careful.  The only thing we would have done differently was have a better “pre-game” plan for the project. At first we kind of jumped into it, but then realized we needed to write our ideas down. Other than that, the overall project was a success.  References:  We would like to reference Honda. We watched their Super Bowl Rube-Goldberg commercial to get a good idea of what a Rube-Goldberg project should demonstrate.