Question

A Bullet of mass m is fired with a velocity ν onto a block of wood of mass M and initially at rest. The final velocity of the system will be

(A) [m/ (m .+ M)]ν 

(B) [M/ (m + M)]ν

(C) [(m +M)/ m]ν 

(D) [(m + M)/ M]ν

Answer 1

Answer is (A) [m/ (m .+ M)]ν

Apply the law of conservation of momentum.