Answers

2014-08-23T23:15:40+05:30
Here no external force is acted (neglect air resistant) hence momentum of system(gun+bullet) is conserved 
initial momentum = finial momentum
let the recoil velocity of gun = v
0.01*0 + 4*0 = 0.01*400 + 4*v
v = -1m/s
hence gun recoil with velocity 1m/s 
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