Re: t-and-f: My third grader's math

[Wayne T. Armbrust]

When I taught introductory physics classes at Ohio State I would 
sometimes put track & field related questions on tests.  Questions 
like:  If a sprinter takes 3.6 seconds to cover the first 30 meters of a 
race, what is his average acceleration?  If he has a mass of 70 kg, what 
average force is he exerting against the track?  Or:  If a hammer 
thrower throws a hammer 80 meters and the initial angle of the hammer 
with respect to the ground was 37 degrees, what was its initial 
velocity?  Ignore air resistance and the height of the hammer at 
release.  The hammer is is a 7.26 kg [I assumed all the weight of the 
hammer was in the ball] metal sphere (head) connected by a wire to a 
handle and is spun in a circular arc before being released by the 
thrower.  If the distance of the head of the hammer from the thrower's 
center of mass is 2.0 m during the spin, estimate the maximum 
centripetal force that the thrower must exert.

--
Wayne T. Armbrust, Ph.D.
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