find the moment of inertia of a point mass 0.005g at aperpendicular distance of 3m from its axis of rotation.

the moment of inertia is 4.5 × 10⁻⁵ kg.m²  

Explanation:

Given that;

point mass m = 0.005 g = ( 0.005 / 1000 ) = 5 × 10⁻⁶ kg

perpendicular distance r = 3m

We know that a point mass doesn't have a moment of inertia around its own axis but, but using the parallel axis theorem, a moment of inertia around a distant axis of rotation can be determined using;

= mr²

so we substitute

= (5 × 10⁻⁶ kg) × (3 m)²

= (5 × 10⁻⁶ kg) × 9 m²

 = 4.5 × 10⁻⁵ kg.m²  

Therefore; the moment of inertia is 4.5 × 10⁻⁵ kg.m²