A uniform stick 1.3 m long with a total mass of 260 g is pivoted at its center. A 3.6 g bullet is shot through the stick midway between the pivot and one end. The bullet approaches at 250 m/s and leaves at 140 m/s. With what angular speed is the stick spinning after the collision?
The Attempt at a Solution
I dont really know what intial condition you would use. Obviously the final condition is the bullet left and the thing is spinning. Also, what would you use for the R of the bullet in calculating moment of inertia? One thought i had was the moment just before the bullet enters the stick the R approaches 1.3/4. So Iw(initial) would be (.0036)(1.3/4)^2(250/(1.3/4)). Then my guess for Iw(final) is (1/12)(.26)(1.3)^2(W) + (.0036)(1.3/4)^2(140/(1.3/4)) where W is what we want.