Problem 5: A uniform disk of mass 4.4 kg and radius 0.89 m rotates about a perpe
ID: 1776695 • Letter: P
Question
Problem 5: A uniform disk of mass 4.4 kg and radius 0.89 m rotates about a perpendicular axis through its center. The disk completes a full rotation every 0.89 second. Six small objects are attached to the disk and rotate with it: Three of the objects, with mass 0.85 kg each, are fixed to the edge of the disk at various locations. Two objects, each of mass 1.3 kg, are at attached to the disk diametrically opposite each other 0.63 m from the disk's center. The sixth object has a mass of 2.1 kg and is attached at the disk's center. Part (a) Find the moment of inertia, in units of kg m*, of the system consisting of the disk and its attached objects, about the disk's axis of rotation Numeric :A numeric value is expected and not an expression. Part (b) Calculate the magnitude of the angular momentum of the rotating system, in units of kgm2ls Numeric :A numeric value is expected and not an expression L=Explanation / Answer
(A) I = (4.4 x 0.89^2 / 2) + 3(0.85 x 0.89^2) + 2(1.3 x 0.63^2) + (2.1 x 0)
I = 4.79 kg m^2
(B) L = I w
w = 2p/T
L = (4.79) (2pi /0.89) = 33.8 kg m^2 / s