PHYSICS-diameter, inertia, and mass (I thought I understood but kept getting wrong answer)

Question

A bicycle rim has a diameter of 0.65 m and a moment of inertia, measured about its center, of 0.19 kg⋅m2

What is the mass of the rim?

Answer 1

I think is the standard approach is to treat the rim as a thin circular loop.

I this case its moment of inertia is given by I = mr²

We are given I = 0.19 kg/m² and d = 0.65 m (meaning r = 0.325 m).

So m = I/r² = (0.19 kg/m²)/(0.325 m)² ≈ 1.8 kg

Answer

The mass of the rim is 1.8 kg