The Rube Goldberg Launch System (writing instructions)

Click here to find out why it is important that STEM students be proficient writers. (Read the account by NASA rocket engineer Norm Chaffee.)

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DISCUSSION

A Rube Goldberg machine is one that does a simple task in an altogether complicated way.  For example, the act of turning on a light via a switch in “Rube Goldberg” style would include as many as a dozen  steps leading up to the switch actuation.  Goldberg’s inventions depicted the series of acts cartoon style.   He assigned a letter, A., B., C., D., etc., to each device in the process leading to turning on the switch.   Below is an example of one of Goldberg’s cartoons.    In a sense, each of Goldberg’s cartoons is an invention, though impractical.  Of course, they would not be worth constructing or patenting. Their value is in the novelty and humor they provide.

Click the picture below to watch an animation of a Rube Goldberg device.

Incidentally, Rube was an engineer.  His creations, though attributed to cartooning, actually exhibit his engineering abilities.  Engineering standards are observed in the inclusion of pulleys, Newton’s laws (including the law of gravitation), heat transfer, pneumatics, and other engineering methods and practices.  Indeed, he made expert use of his education in designing his absurd devices.  In the exercise below, beside each step is listed a science/engineering topic related to the process.

The  Self-Operating Napkin Invention

By Rube Goldberg

The "Self-Operating Napkin" is activated when the soup spoon (A) is raised to mouth, pulling string (B) and thereby jerking ladle (C) which throws cracker (D) past parrot (E). Parrot jumps after cracker and perch (F) tilts, upsetting seeds (G) into pail (H). Extra weight in pail pulls cord (I), which opens and lights automatic cigar lighter (J), setting off skyrocket (K) which causes sickle (L) to cut string (M) and allow pendulum with attached napkin to swing back and forth, thereby wiping chin.

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As a writing exercise, study the drawing below, a complicated process for launching a rocket.  Enter in the blanks the missing step or device in the list of actions.  After completing the list, write a step by step instructional paragraph about the process.  The value of this exercise is to adhere to accuracy, thoroughness, and clarity.  Whether one is baking a cake from a written recipe, or a technician is drafting the steps of a rocket test, failure to be accurate, concise, and thorough leads to a spoiled cake or failed rocket.  “Write what you mean, and mean what you write” is how one person put it.

(Hint:  Several of the steps are included below to assist in analyzing the launch system. Fill in the rest of the steps and devices then compose an instructional paragraph.)  The sketch below is an adaptation of various Rube Goldberg cartoons fashioned into a rocket launch activation mechanism.

1. Electrical Switch                                             (electricity, circuit theory)

Turns on Hot Iron

1. Electric Iron                                                    (heat transfer, convection heating)

Heats Ice Block

1. ____________                                                (change of state – solid to liquid)

Drips water into pan

1. Pan/funnel                                                        (fluid flow)

Channels water into pail

1. Pail                                                                  (equilibrium)

Water in pail  pulls pulley string lifting fulcrum arm

1. Fulcrum – teeter totter                                                (simple machines, the fulcrum)

Drops iron ball

1. Iron ball                                                           (Equilibrium, balance)

Pulls pulley string

1. Pulley                                                              (simple machine - pulley)

Applies force to mallet

1.                                                                         (shock, transfer of kinetic energy)

Strikes boot

1. Boot                                                                (action vs. reaction, Newton’s Laws)

Kicks second boot transfer bars

1.                                                                         (momentum transfer)

Kicks football

1. Football                                                           (projectile motion)

1. ________                                                        (guided application of force)

Guides football trajectory

Pulls on string

1. Cord                                                                (tension)

Pulls scissors handle

1. Scissors                                                           (scissors as inclined plane)

_______________

1.                                                                         (string tension)

Supports bag to be dropped

1. Bag of sand                                                     (Newton’s law of acceleration)

Pulls down scale arm

1. Scale                                                                (Equilibrium)

Pushes torch upward

1. Torch                                                               (Ignition source)

________________

1.                                                                         (the rocket equation)

Launches