A 15.0 g bullet traveling at 520 m/s strikes a stationary 5.1 kg wooden block.the bullet passes through the wooden block and leaves with a velocity of 365 m/s.how fast is the block moving when the bullet leaves it.

Use m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2?

You can assume that he bullet imparted all of the momentum it lost into the block - as you will recall, the momentum before must equal the momentum afterwards - Jerry above me has it right, that is exactly the formula you must solve (you know m1,m2,u1,u2 and v1, so it should be simple to solve for v2, as an interesting exercise, solve the equation for v2 before putting the numbers in and let me know what you get!)

Oh, I did it right? I wasn't so sure... but since I started that chapter... Ok, thanks Cap! :)