# 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.
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.

### 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.

### The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.

### MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

### Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

### Solenoid Valve Basics: What They Are, What They Do, and How They Work

May 13, 2024
A solenoid valve is an electromechanical device used to control the flow of a liquid or gas. It is comprised of two features: a solenoid and a valve. The solenoid is an electric...