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Re: Henry LaMothe



Title: Re: Henry LaMothe
About a year ago I found an interesting problem in a Physics book about Henry
LaMothe (hope I spelled that correctly).  It seems Henry had an act in which
he would dive off a 40 foot tower and belly-flop into 1 foot of water.  It
seems impossible but they had a picture of this act in the book.  Now I can't
remember in which book it was and I have not been able to find it in the books
around my office.  Does anyone know in which Physics textbook I saw this?

Thanks

Russ
This is in the 6th edition of Halliday, Resnick, Walker Fundamentals. They give height as 30 m, water depth as 30 cm and say that M. LaMothe did his act until he was in his 90's.

A related set of interesting problems involve surviving impact on the ground after jumping out of an airplane without a parachute. I got this information from George Benedik and Felix Villars, in Physics With Illustrative Examples From Medicine And Biology, Volume 1, Addison Wesley, 1973, report that the threshold for human survival is when the pressure on impact is less than 50 pounds/square inch. If the fall is onto a person's back of area 3.8 square feet, the threshold force for death is 27,000 pounds = 1.2 x 10^5 N.

In a fall from high altitude, the change in momentum is fixed by the terminal velocity before impact, and the velocity of 0 after what we hope is not "Terminal" impact. Consider the following observations. Do they satisfy this criterion for survival?

"During one of the battalion drops, from 1200 feet on a clear, relatively warm day, an observer noted what appeared to be an unsupported bundle falling from one of the C-119 airplanes; no chute deployed from the object. The impact looked like a mortar round exploding in the snow. When the aidmen reached the spot they found a young paratrooper flat on his back at the bottom of a 3 1/2 foot crater in the snow, which consisted of alternating layers of soft snow and frozen crust. He could talk and did not appear injured; nevertheless, he was air evacuated to a hospital. His only injuries were an incomplete fracture of a clavicle, a chip fracture of L-2, and a few bruises. He was released from the hospital in time to return south with his unit."
Alaska, 1955

"[O]n the frigid 23rd of March, 1944, Flight Sergeant Nicholas Alkemade, an RAF rear gunner [had his bomber set afire] by a German night fighter on a raid over Hamburg. [H]e found that he was unable to reach his parachute, stowed forward in the flaming fuselage. Deciding he didn't care to burn alive, he jumped without a parachute just as the aircraft exploded above him. His altitude was 18, 000 feet. Falling at a terminal velocity of about 120 mph during this 3 1/2 mile fall (which lasted about 90 seconds), he struck the snowy branches of a pine forest and then landed in less than 18 inches of snow, only twenty yards from the bare open ground. Incredibly, his only reported injuries consisted of superficial scratches and bruises, and burns received prior to the jump."

From "Terminal Velocity Impacts Into Snow", R. G. Snyder. Military Medicine 131, 1290-1298 (1966).



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