Question

A bullet of mass 20 g is fired with a velocity of 100 m/s. If the mass of the gun is 10 kg, what is the recoil velocity of the Gun?

Answer 1

Question:

A bullet of mass 20 g is fired from a gun with a muzzle velocity 100 m/s. Find the recoil of the gun its mass is 5 kg.

Required Answer

-0.4m/s

Given data:

• m = 20 g = 0.02 kg
• V = 100 m/s
• M = 5 kg

To find:

• V = ?

Solution:

According to the law of conservation of momentum:

MV+ mv = 0

Putting the values, we get:

⇨5kg × V+ (0.02 kg)x(100 m/s) = 0

or

$\mathcal{⇒5 kg × V = - (0.02 kg)x(100 m/s)}$

$\mathcal{⇒V = \frac{(0.2kg) \times (100m {s}^{ - 1}) }{5kg} }$

⇒0.4m/s

The negative sign indicates that the gun recoils i.e., moves in the backward direction opposite to the motion of the bullet with a velocity of 0.4 m/s.