Question

I cant find out how to solve this problem. I have tried multiple times and get it wrong every time. Please show me how to solve the problem.

An 9.00 g bullet is fired into a 322 g block that is initially at rest at the edge of a table of 1.3 m height. The bullet remains in the block, and after the impact the block lands 1.6 m from the bottom of the table. Determine the initial speed of the bullet.

Answer 1

how long does it take to fall? 4.9t^2 = 1.6, so t = 0.57
so, its horizontal velocity (of block & bullet) is 1.76m/0.57s = 3.08 m/s
Now conserve momentum to find the desired speed.

Answer 2

h = 0.5g*T^2 = 1.3.
4.9T^2 = 1.3,
T = 0.515 s. = Fall time.

d = V*T = 1.6.
V*0.515 = 1.6,
V = 3.11m/s after collision.

M1*V1 + M2*V2 = M1*V + M2*V.
9*V1 + 322*0 = 9*3.11 + 322*3.11,
V1 =