Given data:
mass of the bullet (m) = 25 g = 0.025 kg,
mass of the gun (M) = 0.9 kg,
speed of the bullet (v) =230 m/s,
speed of the bullet (V) = ?
From the given data it is clear that, the momentum is conserved. According to "<em>law of conservation of momentum" </em>the total momentum before and after the collision is equal.
In this problem the momentum before collision (bullet+gun) is zero.
Therefore, after the gun fires a bullet, the momentum must be zero.
Mathematically,
M × V + m × v = 0
where,
M × V = momentum of the gun
m × v = momentum of the bullet
(0. 9 × V) + (0.025 × 230) = 0
0.9 V = -5.75
V = -5.75/0.9
= -6.39 m/s
<em>The gun recoils with a speed of 6.39 m/s</em>
