The relative difference between “polar” and “mean” values of this quantity defines the dynamical ellipticity. A 2-to-2-to-1 ratio of components of this quantity characterizes the Kovalevskaya top. (10[1])In Poinsot’s (10[1])construction, an ellipsoid (10[1])named for this (-5[1])quantity rolls (10[1])without slipping (-5[1])on the invariable plane. A body with three distinct values (10[1])of this quantity (10[4])only has stable (10[1])motion about (10[2])the first (10[1])and third (10[4])“principal” types of a certain construct. The fact that this (-5[1])quantity equals (10[1])the integral of “r-squared dm” (10[1]-5[1])is (10[1])used to prove (10[2])that a displacement (10[3])d changes this quantity by a factor of “m plus d-squared” in the parallel axis (10[1])theorem. (10[1])An analogue (10[1])of Newton’s (10[1])second law states that net torque equals this quantity times angular acceleration. For 10 points, name this rotational analogue of mass. ■END■ (10[3])