What is the recoil speed of a rifle after firing a bullet at 124m/s?

[Heathgirl08]

Physics question, velocity...

Homework Statement

A rifle with a weight 19N fires a .0067kg bullet with a speed of 124m/s. The acceleration of gravity is 9.81 m/s2. Find the recoil speed of the rifle. Answer in units of m/s.

Homework Equations

F=ma, F= m(change in velocity/change in time), Vfinal=Vinitial+at
I really don't know... I don't know any equations with force and velocity.

The Attempt at a Solution

19=(.0067)+(9.81x124)V

 

[nrqed]

Homework Statement

A rifle with a weight 19N fires a .0067kg bullet with a speed of 124m/s. The acceleration of gravity is 9.81 m/s2. Find the recoil speed of the rifle. Answer in units of m/s.

Homework Equations

F=ma, F= m(change in velocity/change in time), Vfinal=Vinitial+at
I really don't know... I don't know any equations with force and velocity.

The Attempt at a Solution

19=(.0067)+(9.81x124)V

Have you seen momentum? This problem is done by imposing conservation of momentum. The value of g is only given so thatyou may figure out the mass of the rifle (they give the weight, not the mass)