Motion System Design

Fair game

Autumn is underway and Farmer Dan is once again taking part in the county fair. This year, he's exhibiting his prized cows and goats. While on break one afternoon he boards a hayride to observe the festivities up close. There are cotton candy and game stands with stuffed giraffes to the left; on the right, square dancers cheerfully do-si-do. But straight ahead is the one attraction Farmer Dan anticipates most: a 70-m high Ferris wheel!

The Ferris wheel requires five tickets, but Farmer Dan only has three. Feeling charitable, the ride's operator challenges Dan that if he correctly determines the Ferris wheel's velocity and total time to complete one revolution, his three tickets will suffice. According to the operator, the Ferris wheel's centripetal acceleration is 5 m/sec2 and the carts should be treated as particles moving at constant speed along a circle. Can you help Farmer Dan out of this jam?

Send your solution to [email protected] by November 8, 2005. For last month's full solution, visit

Readers and problem solvers, we want your feedback! Is there anything about the current delivery of Fun with Fundamental problems/ solutions/prizes that you would like to see changed? Send your input to [email protected].

Win a pedometer

The winner of this month's problem receives a premium pedometer from Omron Healthcare, Bannockburn, Ill. The HJ-112 calculates the number and duration of a person's aerobic steps. For additional information on Omron healthcare products, visit, or for information on Omron electronics and industrial controls, contact Jen Pulins at (847) 285-7257.

HJ-112 FEATURES: • Calories burned and total distance calculated by walker's weight, stride distance, and number of steps • Seven-day data storage for easy progress monitoring • Accurate step measurement when attached to a belt, in a shirt pocket, or in a bag.

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