physics
posted by Elisa .
An 8.00 g bullet is fired into a 180 g block that is initially at rest at the edge of a table of 1.00 m height. The bullet remains in the block, and after the impact the block lands d = 2.2 m from the bottom of the table. Determine the initial speed of the bullet.

initial momentum = final momentum
.008 * V + .18 * 0 = .188 U
where V is initial bullet speed and U is horizontal speed off the table.
Now get U
t is fall time
horizontal distance = U t = 2.2
vertical distance = 4.9 t^2 = 1
t= sqrt (1/4.9)
solve that for t
U = 2.2 / t
V = (.188/.008) U 
420