q disc of mass m and radius R has a concentric hole of radius r. its moment of inertia about an axis through its centre and prependicular to its plane is?
anuradha , 6 Years ago
Grade 11
1 Answers
Arun
Last Activity: 6 Years ago
Consider a ring of radius x and thickness DX of the disc The MI of the ring about a normal axis through which its centre is dI =(2πx.dx.x^2)/π[R^2_r^2]The total MI of the disc is obtained by integrating the above expressionIntegrations I=integration {m/π(R^2-r^2)}.2πx.dx.x^2On solvingI={m(R^2 + r^2)}/2