Question

A bullet of mass 5g is fired at a velicity 900ms from a fifle of mass 2.5 kg .what is thd recoil velocity of the rifle

Answer 1

$\textsf{\huge{\underline{Hello Mate!}}}$

Since mass of bullet is 5 g so on converting it we get, 0.005 kg.

Now, as initially bullet as well as rifle were at rest therefore Total Initial Momentum is "0".

Now, for Total Final Momentum :

= m1v1 + m2v2

= (0.005)(900) + (2.5)v

= 4.5 + 2.5v

$\textsf{\red{T Initial p = T Final p}}$
( where p = momentum )

0 = 4.5 + 2.5v

- 4.5 = 2.5v

- 1.8 m/s = velocity.

Negative sign shows that rifle is going against direction of motion.

$\textsf{\blue{Velocity of rifle is 1.8 m/s}}$

$\textbf{Have great future ahead!}$

Answer 2

$\huge{ \{thanks}$
here is your answer OK ☺☺☺☺☺☺


M1 = 2.5kg (mass of rifle)
M2 = 0.005kg (mass of bullet)

V1 = ? ( velocity of gun)
V2​ = 900 m/s (velocity of bullet)

according to conservation of momentum


M1 * V1 = M2 * V2

2.5 * V1 = 0.005 * 900

V1 = 9 / 5

V1 = 1.8 m/s