A 0.0124-kg bullet is fired straight up at a falling wooden block that has a mass of 3.96 kg. The bullet has a speed of 756 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision with the bullet occurs. As a result of the collision, the block (with the bullet in it) reverses direction, rises, and comes to a momentary halt at the top of the building. Find the time t.

Answer 1

find the time t for what event?

Answer 2

Well the question says the block was falling for time t until the collision, so i assumed just falling time right up to when the bullet hits.
What I figured so far was
a) I found Vbullet by doing mzv1-m2v2
b) then i did vf= vi+at and solved for t.
I could be totally off