Question

A shell of mass 0.02 kg is fired by a gun of mass 100 kg if the muzzle speed of the shell is 80 m/s . what is the recoil speed of the gun?

Answer 1

0.02*100 = 80 *recoil speed of gun
2 = 80 *recoil speed of gun
2/80 = recoil speed of gun
0.025 =recoil speed of gun

hope it helps

Answer 2

Explanation:

Mass of the gun, M = 100 kg

Mass of the shell, m = 0.020 kg

Muzzle speed of the shell, v = 80 m/s

Recoil speed of the gun = V

Both the gun and the shell are at rest initially.

Initial momentum of the system = 0

Final momentum of the system = mv – MV

Here, the negative sign appears because the directions of the shell and the gun are opposite to each other.

According to the law of conservation of momentum:

Final momentum = Initial momentum

mv – MV = 0

∴ V = mv / M

= 0.020 × 80 / (100 × 1000) = 0.016 m/s