PDCA - One Blog

Welcome to the first Dexter cattle blog to disseminate information for members of the Purebred Dexter Cattle Association of North America (PDCA) and for those with a curiosity about Irish Dexter cattle, cattle in general, as well as news from the PDCA. Expressions of opinion are to not be regarded as expressing the official opinion of the PDCA unless expressly stated. Hopefully you will find something here of interest and don't overlook browsing through the archives. Comments are welcomed.

Saturday, November 12, 2005

Cow-Tipping Physics

TIMES ONLINE - Much to the relief of dairy herds, the sport of cow-tipping has been debunked as an urban, or perhaps rural, myth by scientists at a Canadian university. Margo Lillie, a doctor of zoology at the University of British Columbia, and her student Tracy Boechler have conducted a study on the physics of cow-tipping.

Ms Boechler, now a trainee forensics analyst for the Royal Canadian Mounted Corps, concluded in her initial report that a cow standing with its legs straight would require five people to exert the required force to bowl it over. A cow of 1.45 metres in height pushed at an angle of 23.4 degrees relative to the ground would require 2,910 Newtons of force, equivalent to 4.43 people, she wrote. Dr Lillie, Ms Boechler’s supervisor, revised the calculations so that two people could exert the required amount of force to tip a static cow, but only if it did not react.

"The static physics of the issue say . . . two people might be able to tip a cow," she said. "But the cow would have to be tipped quickly — the cow's centre of mass would have to be pushed over its hoof before the cow could react."

Newton’s second law of motion, force equals mass multiplied by acceleration, shows that the high acceleration necessary to tip the cow would require a higher force. "Biology also complicates the issue here because the faster the [human] muscles have to contract, the lower the force they can produce. But I suspect that even if a dynamic physics model suggests cow tipping is possible, the biology ultimately gets in the way: a cow is simply not a rigid, unresponding body."

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