British scientist Barnes - Willis invented the bouncing bomb, inspired by the researchers, describes the stones, toys, and even artillery shells on the water bouncing complex physics behind this behavior.
Early in the 18th century, the Navy gunner put the bounce shells as a military strategy, excluded from the process of sinking enemy ships is to limit the emission angle variables. Brigham Young University in Utah Tad - Professor Truscott and his colleagues said: "During World War II, Barnes - Willis through his bouncing bomb, re-use variables to reduce the military advantage to undermine the big German. dam shells by jumping in the water to avoid anti-submarine torpedo nets. "
They are on the "Physics Today" wrote that with the emergence of toy balls, ducks and drakes have become more tractable, won several jumping has become easier. The researchers said: "The ball is made of flexible plastic, they have a high ability compliance or said deformable for naught phenomenon brought some very interesting change." But with lateral throw and rotating the wrist, several thousand years old and young people throwing stones to the surface of the water, as much as possible to let the stones bouncing on the water. According to the "Guinness Book of World Records" display, ducks and drakes world record 88 times bounce, this record is this year by the American Kurt - Steiner hit.
Truscott said the object-throwing angle depends on the technology of choice thrower, disc throwing stones at the best angle is close to 20 . But the more heavy throwing objects, throwing angle should be smaller. He said: "the object ball harder than the dish actually make sense of previous studies have shown that the upper limit of throwing angle is 18 so the steel shells, only when throwing angle is less than 7 , to produce bounce. . "to allow a selective approach involves the stone circle have a great swing, so that it will push to change the direction after entering the water, began to run up and out of the water. Truscott said: "This method does not generate a lot of bounce times, however, it is still impressive to achieve the object, you throw stones to the surface than the angle must throw stones dish. angle bigger. "
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