PROPERTIES OF MECHANICS: BODY, (PARTICLE) AND RIGID BODY.  

NAME SYMBOL [dimensions]
mass: m ~ [m]
time: t ~ [t]
position:(#) P ~ [L]
velocity:(#) V ~ [L/t]
momentum:(#) mV ~ [m L/t]
angular momentum:(#) r x (mV) ~ [m L2/t]
center of mass:(#) rcm ~[L]
radius of gyration:(#) rcm ~[L]
(#), requiring a vector origin and basis