Halliday, Resnick & Walker — Rotation: Problem Problem_40

Figure 10.17 shows an arrangement of 15 identical disks that have been glued together in a rod-like shape of length \(L = 1.0000 \text{ m}\) and (total) mass \(M = 100.0 \text{ mg}\). The disks are uniform, and the disk arrangement can rotate about a perpendicular axis through its central disk at point \(O\). (a) What is the rotational inertia of the arrangement about that axis? (b) If we approximated the arrangement as being a uniform rod of mass \(M\) and length \(L\), what percentage error would we make in using the formula in Table 10.5.1e to calculate the rotational inertia?