a bullet of mass ..21kg is fired from a gun of a mass 5.6kg. if gun is recoiled at a speed of 2.5 m/s .What speed must the bullet have as it leaves the gun

Answer 1

Assuming the gun/bullet combo was initially at rest, conserve momentum to get

(.21)(v) + (5.6)(-2.5) = 0

I think that's a heavy, slow bullet!