# I am lost, dont know how to solve part 2

1. Oct 28, 2008

1. The problem statement, all variables and given/known data

part -1) A 30-06 caliber hunting rifle fires a bullet of mass 0.0113 kg with a velocity of 765 m/s to the right. The rifle has mass of 4.1 kg.
what is the recoil speed of the rifle as the bullet leaves the rifle? answer in units of m/s. answer is 2.1084 /s

part -2) If the rifle is stopped by the hunter's shoulder in a diatance of 2.52 cm, waht is the magnitude of the average force exerted on the shoulder by the rifle? answer in units of N.

2. Relevant equations

not sure, new user on this website

3. The attempt at a solution

not sure, new user on this website

2. Oct 28, 2008

### Integral

Staff Emeritus
You need to show us some effort.

What do you know about conservation of momentum?

3. Oct 29, 2008

part1) V(bullet) = (m(bullet)v(bullet))/(M(rifle)) = 2.1084 m/s

Part2) J = (F) (deltaT)
J = P(final) - P(inital) = MV(final) - MV(initial) = M(V(final) - V(inital))

4. Oct 29, 2008

### mgb_phys

For the second part you might be better using conservation of energy.
Energy = force * distance.
The hunters shoulder is essentailly a spring receiving the kinetic energy of the moving rifle. You know the mass and initial velocity of the rifle and the final velocity=0.

5. Oct 29, 2008