Question

A bullet of mass `50g` is fired with an velocity of `150m//s`. If the rifle weights `3kg`. What is its recoil velocity?

Answer 1

Here, `m_(1)=50g= 50xx10^(-3)kg, v_(1)=150 m//s`
`m_(2)=3kg, v_(2)=?`
As `m_(1)v_(1)+m_(2)v_(2)=0`
`:. v_(2)= (-m_(1)v_(1))/(m_(2))= ((50xx10^(-3))xx150)/3=2.5m//s`.

Answer 2

momentum of the bullet = Velocity*Mass

= 150*0.05 = 7.5

Recoil velocity of the rifle is = momentum of bullet/ mass of gun

= 7.5 / 3 =2.5

The recoil velocity of the gun is 2.5 m/s