## Science Milestones: The Art and Science of Rube Goldberg

Rube Goldberg was a famous cartoonist who took simple and compound machines which are meant to make tasks easier, and made them overly complex. His cartoons depicted complex machines that worked in an indirect and convoluted way, such as the “Self-Operating Napkin”.

As you raise spoon of soup (A) to your mouth it pulls string (B), 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 sky-rocket (K), which causes sickle (L) to cut string (M) and allow pendulum with attached napkin to swing back and forth thereby wiping off your chin.

### Rube Goldberg Physics

When Goldberg showed his “Self-Operating Napkin” machine to his friend, his friend said it would not work. Using what you know about mechanical advantage and work, prove to Goldberg’s friend that the invention will actually work.

Work (in Joules, J) = Force (Newtons, J) x Distance (m)

Mechanical Advantage of a Lever = Distance from fulcrum to the applied force / Distance from fulcrum to weight lifted

You raise your spoon of soup 0.15 meters with 2 Newtons of force. How much work did you do?

The spoon pulls a string as you move it. How much work is transferred?

The string jerks the ladle, which is a lever. The string is attached 10 cm from the fulcrum and the force is applied 0.5 m from the fulcrum. What is the mechanical advantage?

The spoon throws a cracker past a parrot. The parrot jumps after the cracker, applying force to the perch he is sitting on. The perch spins around throwing the seeds into a pail. The perch is another lever. It has a mechanical advantage of 2. If it would take 0.5 J of work to move the seeds 0.1m without the lever, how much force will be needed with the lever?

The extra weight in the pail pulls a cord, which goes around a pulley and opens and lights an automatic cigar lighter. If the pail can apply 3 N of force to the cord, and the pulley system has a mechanical advantage of 2, how much total force can be applied to the match?

The match sets off the rocket, which causes a sickle to cut the string, allowing a pendulum with attached napkin to swing back and forth thereby wiping off your chin. If 3 N of force is needed to strike the match, will the system work?

Discover the amazing resources and contests at Rube Goldberg.

### Biography

Reuben Lucius “Rube” Goldberg was born on July 4, 1883, in San Francisco, California. He loved to draw and received some basic art instruction when he worked with a sign painter as a young teen. Rather than pursue a career in art, though, he followed his father’s advice and attended the University of California at Berkeley, where he earned his degree in engineering.

Mapping out sewer pipes and water mains in San Francisco didn’t hold Rube’s interest for long, though. He began creating cartoons for local San Francisco papers. He eventually moved to New York where he landed a job as a cartoonist for the Evening Mail.

He used his engineering background to create funny cartoons featuring complicated machines that were described as new inventions to accomplish easy, straightforward tasks through a series of convoluted steps involving chain reactions. The public quickly fell in love with Rube’s inventions.

His work became popular nationwide, as his cartoons were syndicated in hundreds of newspapers across the country. The art world also loved his works, some of which were displayed in the Museum of Modern Art in New York City. Rube even made it to Hollywood, where his move script “Soup to Nuts” introduced a trio who would soon become famous as the Three Stooges.