What is the physical quantity of the time rate of the angular momentum ?

The position of a particle is given by : $\overrightarrow {r\,}  = (\hat i + 2\hat j - \hat k)$ and momentum $\overrightarrow P  = (3\hat i + 4\hat j - 2\hat k)$. The angular momentum is perpendicular to        

A particle moves with a constant velocity in $X-Y$ plane. Its possible angular momentum w.r.t. origin is

Given $V _{ CM }=2\; m / s , m =2\; kg , R =4\; m $

Find angular momentum of ring about origin if it is in pure rolling. $kgm ^{2} / s$

$A$ uniform rod is fixed to a rotating turntable so that its lower end is on the axis of the turntable and it makes an angle of $20^o$ to the vertical. (The rod is thus rotating with uniform angular velocity about a vertical axis passing through one end.) If the turntable is rotating clockwise as seen from above. What is the direction of the rod's angular momentum vector (calculated about its lower end)?

$A$ hollow sphere of radius $R$ and mass $m$ is fully filled with water of mass $m$. It is rolled down a horizontal plane such that its centre of mass moves with a velocity $v$. If it purely rolls