Question

a bullet of mass 0.03 kg is horizontally fired with a velocity 100 m/s from a pistol of mass 1.5 kg. what is the recoil velocity of the pistol?

Answer 1

since initially both the gun and bullet were in rest so their intial momentum was zero now by conservation of momentum law
m1v1 + m2v2 = 0
0.03*100 + 1.5 *V2 = 0
3 + 1.5 V2 = 0
3 = - 1.5 V2
V2 = -2 m/s
(-) sign shows the motion in opposite direction