posted by Evan on .
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 110 bullets/min, the speed of each bullet being 550 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?
FΔt=Δp= mΔv= m[v-(-v)] =2mv
F=2mv/Δt =2•0.008•550/0.55 =16 N