Question

a gun of mass 1000 kg fires a shell of mass 2kg with the velocity of 200 m per second calculate the velocity of recoil of the gun

Answer 1

hope it helps you...

Answer 2

since no external force acts on the system of gun and shell  

thus linear momentum will be conserved  

1000*v+2*200=0+0

v=-0.4 m/s