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Re: dressing up a problem



Pat and Ken Heller at Minnesota have formalized this process...they call
them enriched problems...they even have a workbook for faculty and ta's
if anyone is interested. Their problems, however, are not as enriched as
this one.

joe

On Mon, 3 Nov 1997, Michael Moloney wrote:

Mechanics problems, not always fascinating, can be dressed up on
some occasions, and may become more ineresting to students. Here is
an example.

In 'Tale of a Guinea Pig', [p. 174, ff. Bantam, 1981] Geoffrey Page
tells of having his spitfire pursued in 1944 by a Me-109 near
Lisieux, over France. Page's left leg had become useless due to a
cannon shell fragment, and he was at treetop level, jinking, and
trying to out-turn the German plane. "The Messerschmitt was just on
the edge of a stall when the pilot fired the guns: the recoil slowed
the plane sufficiently to flick over and strike the trees twenty feet
below."
According to Len Deighton, ['Fighter', Ballantine, 1977, p. 91], the
Me-109 carried 2 cannon, each of which fired 0.138-kg projectiles at
a rate of 520 rounds/minute, with a muzzle velocity of 550 m/s, as
well as two machine guns, each of which fired 0.0128-kg projectiles
at 1100 rounds/min with a muzzle velocity of 750 m/s.

Determine the final velocity of the Messerschmitt if its initial
speed was 36 m/s, and the pilot fired all four guns for 2 seconds.


--

Mike

===============================================================
Mike Moloney
moloney@nextwork.rose-hulman.edu
Dept of Physics & Applied Optics (812) 877 8302
Rose-Hulman Institute of Technology Terre Haute, IN 47803
http://www.rose-hulman.edu/~moloney