Mnemonic 1: I Order (Highest to Lowest)

"Ring Holds Disc Solid" → R, H, D, S

• Ring: $MR^2$ (highest)
• Hollow sphere: $\frac{2}{3}MR^2$
• Disc: $\frac{1}{2}MR^2$
• Solid sphere: $\frac{2}{5}MR^2$ (lowest)

Mnemonic 2: Rolling Race (Fastest to Slowest)

"Solid Defends His Rank" → S, D, H, R

• Solid sphere (1st)
• Disc/solid cylinder (2nd)
• Hollow sphere (3rd)
• Ring/hollow cylinder (4th)

Note: The rolling race order is the REVERSE of the I order.

Mnemonic 3: Theorem Applicability

"Parallel for All, Perpendicular for Flat"

• Parallel axis theorem → applies to ALL bodies
• Perpendicular axis theorem → applies only to FLAT (planar) bodies

Mnemonic 4: CM of Curved Bodies (decreasing height)

"Semicircular Ring → Disc → Solid Hemisphere" $\frac{2R}{\pi} > \frac{4R}{3\pi} > \frac{3R}{8}$ $0.637R > 0.424R > 0.375R$

Mnemonic 5: $K^{2}$/$R^{2}$ Values

$\frac{2}{5} < \frac{1}{2} < \frac{2}{3} < 1$ Read as: "solid sphere < disc < hollow sphere < ring"