Question

While firing a bullet, the gun must be held tight to the shoulder.

1. This is a consequence of______

2. Show that recoil velocity is opposite to the muzzle velocity of the bullet.

3. A gun of mass 5 kg fire a bullet of mass 5g, vertically upwards to a height of 100m. Calculate the recoil velocity of gun.

Answer 1

1. Conservation of linear momentum.

2. Let M be the mass of gun and m be the mass of bullet. When gun fires, the gun and bullet acquire velocities V and v respectively.

According to conservation of momentum.

Total momentum before firing = Total momentum after firing

m × o + M × o = mu + MV

O = mv + MV

ie. – MV = mv

V = −mv/M

3. M = 5kg, m = 5 × 10^-3 kg, h = 100m

v² = u² + 2as

0 = u² + 2 × 10 × 100

Velocity of bullet,