Question

a 100g bullet is fired from a 5kg gun with a muzzle speed of 400m per sec find recoil speed of gun​

Answer 1

Answer:

The recoil speed of the gun is -8 m/s.

Explanation:

The mass of the bullet, m = 100 g = 0.1 Kg

The velocity of the bullet, v = 400 m/s

The mass of the gun, M = 5 Kg

Let the recoil velocity of the gun = V

The momentum of the bullet, P₁ = mv = 0.1 × 400 = 40 Kgm/s

The momentum of the gun, P₂ = MV = 5V Kgm/s

∴ Total momentum after firing, P = P₁+P₂

                                                      = 40 + 5V

Total momentum before firing will be zero since the gun is at rest.

By the law of conservation of momentum,

Total momentum after firing = Total momentum before firing

                                 40 + 5V = 0

                                          5V = -40

                                            V = -40 / 5

                                            V = -8 m/s

So the recoil speed of the gun, V = -8 m/s.