pHysics !!
posted by kent .
A 20g bullet is fired horizontally into a 980 g block of wood suspended by a long cord. The bullet sticks in the block and causes the block to swing 15 cm above its initial level.
a) What is the momentum of the bullet before it hit the block?
b) Determine the velocity of the bullet, u, before it hit the block.
c) If the bulletblock system oscillates continuously, what would be the values of T, f, and
w, if the length of the cord is 1.96 m?

you know the height it went, what PE does it have, At the bottom when starting, it had that KE. From that, determine the velocity of block/bullet at impact.
now use conservation of momentum at impact
(M+m)V= momentumbullet
and now determine velocity bullet
Momentumbullet=m*v
c. I am not certain what your w means, angular momentum, or angular freq.
for T, T=2PI sqrt(length/g)
f= 1/T