The Rube Goldberg Project


INTRODUCTION

A Rube Goldberg contraption – an elaborate set of arms, wheels, gears, handles, cups, and rods, put in motion by balls, cages, pails, boots, bathtubs, and paddles, – takes a simple task and makes it extraordinarily complicated. The contraption is named after a cartoonist, Rueben Goldberg, who was famous for drawing these crazy contraptions in the early and mid-1900’s. The humor of his drawings was that the machines were overly complicated and actually make the task much more difficult to accomplish (sometimes like technology today!) Today, the term “Rube Goldberg” is sometimes used to mean any overly complicated way of doing something.

OBJECTIVE

Students will demonstrate both knowledge and the ability to work cooperatively in the design, construction and presentation of a Rube Goldberg machine having a minimum of 8 separate, different steps. The machine has to successfully crack an egg as the final step. Students will incorporate core concepts of mechanics covered in Physics 125 in these steps. The results will be judged by one or two (if we’re lucky) outside judges, in addition to the instructor. One member of the team (chosen by instructor) will do a presentation to explain the steps of the apparatus to the judges.

LOGISTICS

This activity is worth one half of the total lab grade. In addition to an introductory discovery lab, it includes the following components: 1. Initial preliminary plans, in flowchart form - 20 pts, 2. Project Design Report – 20 pts, 3.Successful device implementation, including narration – 60 pts, 4. Final analysis table – 10 pts. 1st Place Team – 20 pts, 2nd Place Team – 10 pts.

CORE CONCEPTS

Your Rube Goldberg device must utilize each of the following core concepts from mechanics for at least one of the required 8 steps. You may not use one step to satisfy two requirements at once. You may not repeat a step, without some sort of change. The required steps are:

1. Kinematics – Some object in the apparatus must execute accelerated motion.

2-3. Two collisions (one elastic and one totally inelastic): In these 2 steps, momentum must be transferred from one element to another in a collision. In one of the steps, the collision must approximate an elastic collision (e.g. carts with magnetic bumpers). In the other, the collision must approximate a totally inelastic collision (e.g. two carts with Velcro bumpers); the two colliding objects must stick together.

4. Impulse: In one step an impulse must be imparted to an object, setting it in motion (this is a category is similar to a collision, and is useful when the collision is neither totally elastic, nor totally inelastic), or just when something hits something else.

5. Energy Transformation: Kinetic to Potential

6. Energy Transformation: Potential to Kinetic

7-8 The remaining steps are at your discretion, but must show one of the core concepts.

RULES AND LIMITS:

  1. No Dangerous/Harmful Equipment/Material. No flame larger than a candle, no mousetraps bigger than those provided in class.
  2. No Preassembled Parts unless approved by instructor.
  3. No Human or Animal Power. Must Be "Self-Powered" (once initiated).
  4. The apparatus must fit into an area equivalent to half a lab table when assembled.
  5. Assembly and storage. You must be able to disassemble (and reassemble) your project each day that you work on it. You will need a large container or cardboard box to store your project materials. Oversize items cannot be stored in the lab.
  6. The machine must not launch, shoot or catapult anything against people, walls, or the ceiling.
  7. Any all messes created by your machine must be cleaned up promptly by you!
  8. And did we mention no live animals?

SCHEDULE (See Syllabus)

RG1: Preliminary Plan and Flowchart: Meet with your team to brainstorm ideas for the Rube Goldberg machine, using ideas generated from the previous “Mini Rube” discovery lab. The apparatus must have 8 separate steps, 6 of which show the core concepts listed above. Your preliminary plan will involve preparing a flowchart to represent the specific step-by-step progression of the Rube Goldberg machine. The flowchart is due at the end of the lab. See Figure 2 for an Example flowchart.

Your flowchart should:

  • Have a logical flow of steps that are plausible to build
  • Should include some detail about the process
  • Should include an estimate of required materials for each step
  • May be drawn clearly and concisely on a clean, unlined, unripped sheet of paper,OR
  • May be created using computer software (if so, provide software and laptop).

RG2Formal Design Report: The team can begin work on this component as soon as the flowchart has been approved by the instructor and returned. At this time, the official team “narrator” will be appointed by the instructor. All team members must be present to work on this document until the official end of the lab OR hand in finished document before leaving. This report will have the following sections:

  • Introduction of apparatus
  • Description of materials and discussion of choice of those materials
  • Explanation of operational steps and how they will illustrate core concepts
  • Discussion of any anticipated problems and possible resolutions
  • Detailed delegation of duties among team members
  • Drawing of apparatus, on a clean, unlined, unripped sheet of paper (similar to Figure 1 at end of schedule, only without the lines).

RG3 Construction and Troubleshooting: All team members must be present for these 3 sessions OR until you can show a working Rube Goldberg apparatus (no eggs for trials please). Your team should be also be prepared to spend time outside of thelab working on the construction and troubleshooting phase. The physics lab is heavily used during the semester and use of the lab outside of scheduled lab time is NOT guaranteed.

RG4 Contest and Analysis Table: You will have one hour to get your Rube Goldberg apparatus up and running. No eggs until the contest please! The order of contests will be determined by drawing lots. The final completed analysis table is due at this time Good luck!

Figure 1. Example Drawing

Figure 2. Example Flowchart

Step / Description / Core Concept / Explanation / How Energy is Lost

Analysis Table

1