NEET2010PhysicsRotational MotionActual
From a circular disc of radius R and mass 9 M , a small disc of mass M and radius R 3 is removed concentrically. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through its centre is
Options
- A40 9 MR ^2
- BMR ^2
- C4 MR ^2
- D4 9 MR ^2
Correct answer
A. 40 9 MR ^2
Step-by-step solution
The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through its centre aligned I & = I ₁- I ₂ & = 9 MR ^2 2 - MR ^2 18 & = 81 MR ^2- MR ^2 18 & = 40 MR ^2 9 aligned