Question

A 6.0-g bullet leaves the muzzle of a rifle with a speed of 336 m/s. what force (assumed constant) is exerted on the bullet while it is traveling down the 0.83-m-long barrel of the rifle?

Answer 1

The work done on the bullet is force•distance. This is also equivalent to the energy it has leaving the muzzle (work energy theorem). This kinetic energy is (1/2)(0.006kg)(336m/s)^2=338.7J. Then 338.7J=F•0.83m
F=338.7/0.83=408N