Figure shows three uniform discs, along with their radii R and masses M. Rank the discs according to their rotational inertia about their central axes, greatest first.
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$\text{I}=\frac{1}{2}\text{MR}^2$
- $\Big(\frac{1}{2}\times26\times2\times1\Big)\text{kgm}^2=13\text{kgm}^2$
- $\Big(\frac{1}{2}\times7\times2\times2\Big)\text{kgm}^2=14\text{kgm}^2$
- $\Big(\frac{1}{2}\times3\times3\times3\Big)\text{kgm}^2=13.5\text{kgm}^2$
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