a 15gram bullet moving at 300m/s pass through z 2 cm thick sheet of foam and emerges with a speed of 90m/s find average force impeded its motion through the plastic.

Answer 1

Avg force * thickness
= work done by bullet
= kinetic energy loss

Avg. force =
0.015 kg*(1/2)*(300^2 - 90^2](m^2/s^2)/0.02 m
= 3.07^10^4 N