Question

a bullet of mass 20g is horizontally fired with a velocity of 150m/s frm a pistol of mass 2kg. What is the recoil velocity of the pistol?

Answer 1

m1=20g =0.02 kg
v1=150
m2 =2kg
v2=?
m1v1=m2v2
0.02*150=2*v2
v2=150*0.02/2
v2=1.5

Answer 2

m1v1=m2v2+m3v3

2.2 kg*0 m/s=2kg(v2)+.2kg*150

-2(v2)=30

v2=-15 m/s