Motion System Design

Uplifting experience

It happened one Saturday afternoon. Jake Baloney was walking home with a friend, after a full day of pizza and cake eating at another friend's 8th birthday party. All the children received balloons.

Suddenly, Jake's friend tells him, “Get a load of this!” He unties his balloon, inhales a big dose of helium, and declares, “I am a tiny mousey with a tiny little voice!” Well, Jake is so entertained by his friend's outrageous claim uttered in the silliest of high voices that he completely forgets himself and lets go of his balloon.

If it takes Jake five seconds to notice his balloon has slipped away, how fast is the balloon going when he finally takes note? Will he be able to catch the balloon? Assume Jake was holding it at shoulder height, the string is too hard to catch, and that Jake will need to contact the actual inflated balloon to stop its escape.

E-mail your answer to [email protected] by March 15. For solutions and winners to previous problems, visit

Win a pocket multimeter

The winner of this month's problem receives a pocket digital multimeter from Meterman Test Tools, Everett, Wash. The PM55 series measures ac/dc voltage, resistance, capacitance, frequency, and microamp current. For additional information, call (877) 596-2680 or visit Meterman's website at

PM55 Titanium FEATURES

  • Audible indicator and bar-graph display alert users when detecting ac voltage
  • Option of low or hi-Z input impedance
  • Safety rated to CAT III and cULus levels
  • Accurate to 0.5%; weighs less than 3 oz.
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