Motion System Design
Fun With Fundamentals: Problem 248

Fun With Fundamentals: Problem 248

Get ready for a totally tubular challenge.

Problem 248: Tanks a lot

Over the past six years Patricia’s Pet Paradise has performed so impressively that the owners, Peter, Paul, and Patty, were able to raise not only rare fish and fowl, but also some much needed venture capital to keep their lively business growing. They used the funds to build a Web site and a 5,000-sq ft addition. And today is moving day. The only problem is that emptying the sixteen 500-gallon fish tanks is taking longer than expected. And filling them up again could take even longer.

Patty says the one-inch tubing they’re using to empty the tanks just isn’t cutting it. After starting another siphon and swallowing a tetra or two, Peter agrees. Paul pipes in and says, “Hey, I got it! Get the bigger tubing. It’s twice the size, so we’ll be done twice as fast!” Patty and Peter like the idea, but insist that doubling the tubing diameter won’t necessarily double the speed. Patty the pessimist thinks it will only help a little bit, but Peter is positive they’ll be done at least five times faster.

Who’s right and why?

Solution to problem 247: Gold grief, June, 2001.

Winners circle

Fun problem 246: SHIPS AHOY May, 2001
WINNER: Bob Dykes, Urbandale, Iowa

BOB’S PRIZE: MechPack-2000 software from UNIK Associates, Milwaukee, Wis.,

Reduce hours spent calculating to minutes. MechPack-2000 helps determine the capacity of flat belts, size pulleys, convert belt speed to rpm, and quickly calculate many other useful factors. Most programs use English and metric units, and on-line help and phone support are available.

Puzzle us

Get your creative juices flowing and send us your original problems and support are available. solutions. If we publish yours, you’ll win a prize.

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