Question

Seven identical discs are arranged in a planar pattern, so as to touch each other as shown in the figure. Each disc has mass ‘m’ radius R. What is the moment of inertia of system of six discs about an axis passing through the centre of central disc and normal to plane of all discs?

• A. 100 mR2
• B. $55\ \frac{mR^2}{2}$
• C. $85\ \frac{mR^2}{2}$
• D. 100 mR2

Answer 1

Answer: (B)

$55\ \frac{mR^2}{2}$

Answer 2

The correct answer is (B) : $55\ \frac{mR^2}{2}$.