Question

A rifle of mass M is initially at rest, but is free to recoil. It fires a bullet of mass m with a velocity +v relative to the ground.After the rifle is fired, its velocity relative to the ground is??m/Mv.?mv/(M+m).?mv/M.?v.

Answer 1

Answer:

$V=-\dfrac{mv}{M}$

Explanation:

Given that

Mass of rifle = M

Initial velocity ,u= 0

Mass of bullet = m

velocity of bullet =  v

Lets take final speed of the rifle is V

There is no any external force ,that is why linear momentum of the system will be conserve.

Initial linear momentum = Final  linear momentum

 M x 0 + m x 0 = M x V + m v

0 =  M x V + m v

$V=-\dfrac{mv}{M}$

Negative sign indicates that ,the recoil velocity will be opposite to the direction of bullet velocity.