Question

Five particles of mass 2 kg are attached to the rim of a circular disc of radius 0.1 m & negligible mass. Moment of inertia of the system about the axis passing through the centre of the disc & perpenducular to its plane is:

• A. 1 kg-m2
• B. 0.1 kg-m2
• C. 2 kg-m2
• D. 0.2 kg-m2.

Answer 1

Answer: (B)

0.1 kg-m2

Answer 2

As the mass of disc is negligible thererore only moment of inertia of five particles will be considered.

$I = \sum m r ^ { 2 } = 5 \mathrm { mr } r ^ { 2 } = 5 \times 2 \times ( 0.1 ) ^ { 2 } = 0.1 \mathrm {~kg} - \mathrm { m } ^ { 2 }$