A question from lecture: can/would a penny dropped from the top
of the Empire State Building kill a pedestrian at ground level?
This a very old and question that has persisted in American culture
for generations since the thrill of the days the this building
reigned as the world’s tallest. But let’s play physicist and reduce
the problem to evaluate the potential outcome and assume that you
could drop a penny from the height of the Observation Deck on the
102nd floor (1,250 ft, 381 m).
Modern pennies weigh 2.5 grams, but prior to 1982 the US Mint
struck pennies in pure copper that weighed 3.11 grams. Use the
pre-1982 weight to best address the original notion of killer
pennies. Pennies have a diameter of 0.750 in (19.1 mm) and a
thickness of 1.52 mm.
a) A falling penny likely tumbles. Calculate the maximum and
minimum terminal velocities that a penny could achieve at different
orientations to get some boundaries on the problem, expecting the
actual velocity to fall somewhere between the two extremes.
b) Using the maximum terminal velocity that you found, calculate the energy a penny would impart on impact with your head, and interpret the
potential lethality of such an impact?
A question from lecture: can/would a penny dropped from the top of the Empire State Building...