I have no clue on how to approach this. The professor only discussed centripetal acceleration and angular velocity (As in $2πr\over T$ $= ωr$). Does the acceleration along the axis of the drum act in the same way that centripetal acceleration does? I understand that the angular velocity in this case is $ωR$, and the derivative of that is the angular acceleration, but how to I find $ω$? How does $a$ affect the period, and how does its position (In this case along the axis) affect that?