An 8.00 g bullet is fired into a 250 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 = 1.8 m from the bottom of the table. Determine the initial speed of the bullet.

Answer 1

An almost identical problem has been answered twice. See:
http://www.jiskha.com/display.cgi?id=1290391597

Answer 2

Calculate how long it takes the block to reach the floor.

1.00 m = (g/2) t^2
t = 0.452 s

Then calculate the horizontal velocity component as it leaves the edge of the table
Vx = 1.8 m/0.452s = 3.98 m/s

Then use conservation of momentum to get the velocity of the bullet, v.

m v = (m+M) Vx

m is the bullet mass and M is the block's mass.

v = (258/8) Vx = ___