Moment of inertia of a uniform solid sphere
= Moment of inertia of a uniform solid sphere
{title2=$I=\frac25Ma^2$}
A uniform solid sphere of mass $M$ and radius $a$ has the indicated <moment of inertia> about any diameter. Integrating the squared perpendicular distance against uniform <mass density> gives $I=8\pi\rho a^5/15=2Ma^2/5$. It is different from the value for a thin spherical shell and determines the rotational contribution to <kinetic energy> during <rolling without slipping>.