Question

revolver of mass 500g fires a bullet of mass 10kg with a speed of 100m/s find momentum of bullet . initial momentum of bullet and revolver system. recoil velocity of the revolver​

Answer 1

Given :-

▪ Revolver of mass, m = 0.5 kg [ 1kg = 1000 g ] fires a bullet of mass, M = 10 kg with a speed of v = 100 m/s.

To Find :-

▪ Momentum of bullet.

▪ Initial momentum of bullet and revolver system.

▪ Recoil velocity of the revolver.

Solution :-

We know,

⇒ Momentum = mass × velocity

⇒ Momentum of bullet = 10 × 100

⇒ Momentum of bullet = 1000 kg.m/s

Hence, The momentum of the bullet is 1000 kg.m/s.

In the case 2, we have to find the initial momentum of bullet and revolver system before firing. But first, let me clear it fast that before firing, both the revolver and bullet were at rest, so the Momentum is zero.

∴ Initial Momentum = 0 kg.m/s

In the case 3rd we have to find the recoil velocity i.e., velocity of the gun after firing.

We have, after firing

• Mass of bullet, M = 10 kg
• Velocity of bullet, v = 100 m/s
• Mass of revolver, m = 0.5 kg
• Velocity of revolver, v₀ = x

Let us find the momentum of the system after firing.

⇒ p = Mv + mv₀

⇒ p = 10×100 + 0.5v₀

⇒ p = 1000 + 0.5v₀

According to the law of conservation of momentum,

⇒ Momentum before firing = Momentum after firing

⇒ 0 = 1000 + 0.5v₀

⇒ 0.5v₀ = -1000

⇒ v₀ = -2000 m/s

That's too fast, that you may break your wrist.

∴ Recoil Velocity of revolver is -2000 m/s