Machinedesign Com Sites Machinedesign com Files Uploads 2013 05 293 Foorball Fundy Solution

Learning Resources

Fun with Fundamentals Puzzler: Free for ball

Nov. 1, 2006

If the ball's spin is directed as it tumbles towards one very tightly-covered receiver, and it's gyrating at Ψ = 4 rad/sec, what is its angular velocity? See if you can calculate answer.

Elisabeth Eitel

See the previous problem: This ship is a-sailing.

Every November, fans gather for the Otheta State vs. Cactus U match-up. This year, it's late in the first quarter — third and ten — and OSU's Johnny T. Jectrie fades back to pass. He lays out a tight spiral, but a Cactus rascal deflects the ball at the line of scrimmage — imparting an end-over-end tumble to the ball's motion.

If the ball's spin is directed as shown as it tumbles towards one very tightly covered receiver, and it's gyrating at Ψ = 4 rad/sec, what is its angular velocity?

Assume that the ball's ratio of axial to transverse moments of inertia is one third, measured with respect to the center of mass.

Show me the solution.

About the Author

Elisabeth Eitel

Elisabeth Eitel was a Senior Editor at Machine Design magazine until 2014. She has a B.S. in Mechanical Engineering from Fenn College at Cleveland State University.