Question

Calculate the recoil velocity of a rifle with a mass of 5.00 kg (including the bullet) after it fires a 0.005 kg bullet at a speed of 300 m/s ?

Answer 1

Given :

Velocity of bullet, $v_b=300\ m/s$.

Mass of bullet, m = 0.005 kg.

Mass of rifle, M = 5 kg.

To Find :

The recoil velocity of the rifle.

Solution :

Since, their is no external force is acting.

So, momentum of the system will be conserved :

Initial momentum = Final momentum

m(0) + M(0) = m(300) + Mv

$v=-\dfrac{300m}{M}\\\\v=-\dfrac{300\times 0.005}{5}\\\\v=-0.3 \ m/s$

Therefore, recoil velocity of the rifle is 0.3 m/s.

Hence, this is the required solution.