At one instant, force F with arrow $=6\mathrm{.}0$ j N acts on a $0\mathrm{.}50$ kg object that has position vector

r with arrow $=(9\mathrm{.}0$ i hat $9\mathrm{.}0$ k$)$ m

and velocity vector

v with arrow $=(2\mathrm{.}0$ i hat $+2\mathrm{.}0$ k$)$ m$/$s$.$

$($Express your answers in vector form.$)$

$($a$)$ What is the angular momentum of the object about the origin?

l with arrow $=$

kg $$ m$2/$s

$($b$)$ What torque acts on it$?$

vector tau $=$

N $$ m