Answer:
The rotational inertia of the system is 1.8 kg.m².
(b) is correct option.
Step-by-step explanation:
Given that,
Mass of disk = 7.0 kg
Radius = 0.65 m
Mass of clay = 2.1 kg
Distance = 0.41 m
We need to calculate the rotational inertia of the system
Using formula of rotational inertia

Where, I= the moment of inertia of a solid disk
I'=the moment of inertia of lump of clay
Put the value into the formula



Hence, The rotational inertia of the system is 1.8 kg.m².