posted by sam .
It is well known that bullets and other missiles fired at Superman simply bounce off his chest. Suppose that a gangster sprays Superman's chest with 8 g bullets at the rate of 105 bullets/min, the speed of each bullet being 450 m/s. Suppose too that the bullets rebound straight back with no change in speed. What is the magnitude of the average force on Superman's chest from the stream of bullets?
mv = 2x(0.008kgx450m/s) = 7.2kgm/s
=105(7.2)/min = 756 (kgm/s)/(min x (60s/1min))