1. Rube Goldberg Device: THE SLINGSHOT BANDIT By Tim Reed, Andrew Burks, Alan Hancock and Kevin Reed

2. The Slingshot Bandit Objective: Design and build a Rube-Goldberg device that will perform a simple task of your choosing. The device should perform this task in three or more distinct steps. Each step should demonstrate an energy conversion process which you can analyze. Your team is limited to a budget of $20 for supplies. You are responsible for assigning a reasonable cost to everything you use, whether or not you actually purchase it. The one exception is items that you already own that you use as part of your device but do not modify in any way. These may be used at no cost. The device must be original - i.e. not built from a kit.

3. Purpose To effectively help the stalled race car finish the race through a series of steps and energy conversions. The device consists mainly of wood for support and ramps, a tape measurer, a hot wheels car, marbles, string, glue and nails.

4. OBJECTS IN USE

5. Demonstration The marble is dropped into the chute. The marble travels down two ramps, hits the padded ramp and collides with another marble of larger size. The larger marble rolls down the ramp and triggers the tape measurer to contract. The contraction of the tape measurer causes a string connected the car to pull the car down the ramp and through some dominos.

6. Energy Conversions PEg to KE when the ball is dropped and rolls down the ramps. Friction force between the wood and the marble resulting in Eloss, PEg + KE = KE when ball is airborne. PE(elastic)+ KE(ball) = KE(string) PE(car) + Win(string) = KE(car)

7. Collisions Collisions play an important role in our project. The elastic collisions of the marble and the wood have a high coefficient of restitution, so we padded the final ramp to decrease the coefficient of restitution between the ball and the wood so it wouldn’t jump over the last marble. The collision between the smaller marble and the larger marble on the ramp is an elastic collision where the smaller marble transfers some of its momentum to the larger one causing the larger one to have it’s own momentum, enough to flip the switch to the tape measurer.

8. Conclusion We built a Rube Goldberg device. It utilizes the energy conversions, collisions and simple machines. It was cheap. We used some recycled wood, a bag of marbles, glue, nails, some dominos, a cheap tape measurer, tape and a hot wheels car.