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Bloomfield Explains Physics of Heroic Catch
2012-07-18 14:56:54
From MSNBC:

"The girl fell about 25 feet, which took about 1.25 seconds. The man stopped her fall in about 3 or 4 feet, which took about 0.1 second, depending on the stopping distance and how he supported her. So, she accumulated downward momentum over about 1.25 seconds and gave that momentum to the man (and ground) in about 0.1 seconds," Bloomfield told Life's Little Mysteries.

For Bernard to bring the girl's body to a stop in one-twelfth of the time she spent accelerating toward him — that's 0.1 seconds of stopping time, compared to 1.25 seconds of falling time — he had to exert an upward force 12 times greater than her (downward) weight. (Pushing upward is how you slow a falling body to a stop.) That means, "If she weighs 50 pounds, the man and ground must push up with an average of 12 times that force, or 600 pounds."

For more, see:

http://www.msnbc.msn.com/id/48217787/ns/technology_and_science-science/#.UAb0LKNdAtU

http://www.livescience.com/21667-bus-driver-catches-falling-girl.html