At time t$,=9\mathrm{.}60$t $-(6\mathrm{.}60$t $+1\mathrm{.}60$t $)$ gives the position of a $3\mathrm{.}0$ kg particle relative to the origin of an xy coordinate system $($ is in meters and t is in seconds$).($a$)$ Find the torque acting on the particle relative to the origin at the moment $1\mathrm{.}49$ s $($b$)$ Is the magnitude of the particle$$s angular momentum relative to the origin increasing, decreasing, or unchanging?