A gun weighing 25 kg fires a bullet weighing 30 g with the speed of `200 ms^(-1)` . What is the speed of recoil of the gun?

Explanation

Mass of the gun M = 25 kg
Mass of the bullet `m = 30g = 30 xx 10^(-3) kg`
Speed of bullet `v = 200 ms^(-1)`
Speed of gun V = ?
The motion is in one dimension. As per law of conservation of momentum,
`MV = mv = 0`
`V =(-mv)/(M)`
` V = (-30 xx 10^(-3) xx 200)/(25) = - 240 xx 10^(-3) ms^(-1)`
The negative sign shows that the gun moves in the opposite direction of the bullet. Further the magnitude of the recoil speed is very small compared to the bullet.s speed.