Conservation of Angular Momentum and Uniform Rod

[peaceandlove]

Homework Statement

A small 0.157 kg block slides down a frictionless surface through height h = 0.307 m and then sticks to a uniform vertical rod of mass M = 0.397 kg and length d = 2.78 m. The rod pivots about point O through angle θ before momentarily stopping. Find θ.

Homework Equations

Equation 1: I= (1/3)Md^2 + md^2
Equation 2: v=(2gh)^(1/2)
Equation 3: W=m(block)dv/I
Equation 4: arccos(1 -(I*W^2/[d*g(2m + M) ]))

[I and W are for the road and block system]

The Attempt at a Solution

Using equation 1, I found I to be 0.02727 kg*m^2. Then I found W to be 4.3357 using equation 2 and 3. I then plugged in the values into equation 4 and got 40.50412 degrees, but apparently I'm doing something wrong.

 

[peaceandlove]

Nevermind!