Question

from a rifle of mass 78kg, a bullet of mass 60g is fired with an intial velocity of 54 m/s. calculate the initial recoil velocity of the refile​

Answer 1

Given :-

Mass of Gun = M = 78 Kg

Mass of bullet = m = 60 g = 0.06 Kg

Velocity of bullet = v = 54 ms-¹

Let the recoil velocity of gun = V

As we know that when bullet will be fired the momentum of system will be conserved.

By Conservation of Momentum,

MV = -mv

Directions are opposite.

78(V) = -[(0.06)(54)]

V = -[3.24]/78

V = -0.041 ms-¹

Hence,

The recoil velocity of gun = V = -0.041 ms-¹.

Here, Negative sign indicates that the motion of gun will be in opposite direction of that of the motion of bullet and we are taking motion of bullet as positive.