An elastic ball that bounces on water, the Waboba, flattens like a pancake when it hits the water surface, increasing its lift and propelling it upward.
A toy ball that skips on water far easier than the best skipping stone is the inspiration for a line of research that's caught the attention of the U.S. Navy.
The Waboba (named for its description, the "water bouncing ball") is a tennis ball-sized toy that can't bounce on land, but jumps like a champ in a lake, ocean or swimming pool. Brigham Young University physicist Tadd Truscott first noticed the toy while shopping with his son at a dollar store.
"We were like, 'Oh, we gotta try that,'" Truscott told reporters here Tuesday (March 4) at the March meeting of the American Physical Society. [Video: See the Water-Bouncing Ball]
The ball worked as advertised, skipping so readily across the water that it sometimes looks like it's rolling. For a physicist, the next natural question is: How? Now, Truscott is funded in part through the U.S. Navy's University Laboratory Initiative to answer that very question.
Skipping stones and bouncing balls
Like many people, Truscott and his son enjoy trying to skip rocks across smooth water. The physics of rock-skipping is fairly easy to explain: You need a flat rock thrown with the perfect rotation. This rotation gives the stone stability, allowing it to hit the water at the correct angle — 20 degrees for the maximum possible skips. The record in the Guinness Book of World Records for most skips was set in 2007 by Pennsylvania man Russell Byars, who skipped a stone a stunning 51 times.
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