Help Solve Impulse Problem w/ Pendulum Bob

[Kudo Shinichi]

HELP!Impulse problem

Homework Statement

A bullet of mass m and speed v passes through a pendulum bob of large mass M and emerges with speed v/2. the bob is at the end of a sting of length l.What impulse is delivered to the bob by the bullet in this case.

The Attempt at a Solution

impulse=momentum change=P_f-P_i
therefore,
impulse=(m(v/2)+Mv')-mv

However, I don't think it is the final answer for this question, but I don't really know how to continue... can anyone help me with this question? thank you very much.

 

[djeitnstine]

I see nothing is wrong. The bullet comes in with v while the bob has v=0 then the bullet exits with v/2 and then the bob has a velocity of v' (or some velocity v)

 

[Kudo Shinichi]

I see nothing is wrong. The bullet comes in with v while the bob has v=0 then the bullet exits with v/2 and then the bob has a velocity of v' (or some velocity v)

thank you very much. I am just making sure.