Rotation of a Rigid Object about a fixed axis

[XwakeriderX]

Homework Statement

A wheel is comprised of two 50.0 cm long thin rods of negligible mass and a thin metal ring with a mass of 10.00 kg, mounted on a very low friction bearing. A 100 gram lead weight is shot horizontally at the stationary wheel with an initial speed of 50.0 m/s and sticks to the rim of the wheel. What is the rotational speed of the wheel plus lead mass immediately after the collision? Give your answer in revolutions/second.

Homework Equations

L_f=(I_a + I_b)W_f

The Attempt at a Solution

I know of to find the moments of inertia I am just confused about how to find L_f. The bullet would be travelings in a linear momentum not angular. How can i find this value?

 

[rock.freak667]

I think you should just use conservation of energy.

You can get the total moment of inertia I, the equation 0.5Iω²=0.5mv² to get ω.