Question

From a rifle of mass 4 kg, a bullet of mass 50 g is fired horizontally with an initial velocity of 40 m/s. calculate the initial recoil velocity of the rifle.

Answer 1

let
M = mass of gun = 4kg
m = mass of bullet = 50g = 0.05 kg
V = recoil velocity
v = jnitial velocity of bullet = 40m/s
total momentum before interaction = total momentum after interaction

=> 0 = MV + mv

=> MV = - mv

=> 4×V = -0.05 ×40

=> V = -0.5 m/s

hints://
initial momentum is zero because initial the system is in rest.

Answer 2

Here ur answer.Hope u get it...