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Physics Experiment

Image Credit: sunnyUK, Creative Commons.

The science of rolling objects has a long history (see references below), and you can contribute by doing a few rolling experiments (races) and sending us the results. We'll compile the results into a big table and see what we can learn about which objects roll the fastest---theory predicts that the obvious features such as mass, radius, or shape of incline don't matter as much as subtler things like the distribution of mass within the object, or the fraction of the total mass that is actually rolling. You can even submit the link to a youtube video of your rolling race---we'll vote on the best one and send the winner a fabulous physics toy kit as a prize. So go to your nearest skateboard park or wheelchair accessible ramp, or just make your own ramp, and get rolling!

Pick any 3 objects from the list below and race them down a ramp--then let us know what wins. If you don't have a ramp, you can make your own by propping up one end of a board with some books.



Image Credit: LabGP & SigOther,
Creative Commons.
  • tennis ball
  • bicycle wheel
  • marble
  • basketball
  • car tire
  • can of soup
  • ball bearing
  • hula hoop
  • spool of thread
  • marker
  • egg
  • gumball
  • chapstick
  • empty soda can
  • full soda can
  • half-empty soda can
  • jar filed with soapy liquid
  • jar filled with water
  • skateboard
  • person on skateboard (but not pushing off the ground)
  • person on bike (but not pedalling)
  • tricycle
  • person on tricycle (but not pedalling)


Image Credit:
Melody Kramer,

Ready, Set, GO!

Send us your data

Rolling References
Kaye M. Elsner, "Dispense With Misconceptions About Inertia: Have A Race!", TPT, Vol. 30, # 2, Feb. 1992, p. 108.
Mario Iona, "Friction When Rolling", TPT, Vol. 19, # 3, Mar. 1981, p. 154.
David Kagan, "The Shaken-Soda Syndrome", TPT, Vol. 39, May 2001, p. 290.
Robert P. Lanni, "Grandma Brown vs. Chicken Soup", TPT, Vol. 16, # 8, Nov. 1978, p. 553.
Robert H. March, "Who Will Win the Race?", TPT, Vol. 26, # 5, p. 297, May 1988.
Cruse Melvin, "Downhill Races", TPT, Vol. 40, # 4, p. 222, (April 2002), and "Correction" TPT, Vol. 40, # 6, p. 325, Sept. 2002.
Stanley J. Micklavzina, "It's in the Can: A Study of Moment of Inertia and Viscosity of Fluids", Physics Education, Vol. 39, # 1, Jan. 2004, p. 38.
Adam Niculescu, "A Rolling Sphere Experiment", TPT, Vol. 44, # 3, March 2006, p. 157.
Robert Shafer, "Downhill Races Revisited", TPT, Vol. 42, # 6, Sept. 2004, p. 324.
Jordi Solbes, Francisco Tarin, "Which Reaches the Bottom First?", TPT, Vol. 46, # 9, Dec. 2008, p. 550.
W. F. D. Theron, "The Rolling Motion of an Eccentrically Loaded Wheel", AJP, Vol. 68, # 9, p. 812, Sept. 2000.
"239, "And the Winner Is...", Mad About Physics, Christopher P. Jargodzki and Franklin Potter, p. 95, 231.

The following organizations contributed content to this theme:
RAFT The Sloan Career Cornerstone Center Society of Physics Students APS NISE Physica Central comPADRE Flat Stanley Project Talking Science Science Comedian Berkeley Lab Science @ Cal

To learn more about how your organization can contribute content to the Year of Science Web site, please contact us at admin@copusproject.org.