Lo=MO(m)=r×m 式中 r=xi+yj+zk my=mv.i+mv.i+mv. k 所以 Mo(my)=romy= x mmy mlyv-zv )i+m(zvr -xv)j+m(xv -yvr)k 因此,动量矩在坐标轴上的投影,即对坐标轴之矩为 dz di M(mv)=mlyv-zv,)=m(y-z dx dz M,(mv) =m(zv -xv)=m(2-x dy dx M(mv)=m(lxv,-y)=m(x-yLO = MO(mv) = r×mv r = xi + yj + zk mv = mvxi + mvy j + mvzk M (mv ) r mv O = × mvx mvy mvz x y z i j k = m(yv zv )i m(zv xv )j m(xv yv )k = z − y + x − z + y − x 式中 所以 因此，动量矩在坐标轴上的投影，即对坐标轴之矩为   = − = − = − = − = − = − ) dt dx y dt dy M (m ) m(xv yv ) m(x ) dt dz x dt dx M (m ) m(zv xv ) m(z ) dt dy z dt dz M (m ) m(yv zv ) m(y z y x y x z x z y v v v