- #1
thebigbang
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Homework Statement
A large disk of mass M and radius R is spinning like a CD of merry-go-round - that is, about an axis perpendicular to the plane of the disk. It is rotating at an angular velocity (omega initial). At some instant, a sphere of mass M/4 , which is initially not rotating, is dropped onto the disk at a distance of 3R/ 4 from the center. The sphere sticks to the disk and begins rotating with it. Find the final velocity of the disk-sphere combination.
Homework Equations
solid cylinder = I = 1/2 mr squared
solid sphere - I = 2/5 mr squared
(not sure if these are the correct inertia formulas)
The Attempt at a Solution
i have no idea...i don't even know how to start the problem...should i find inertia of disk first?