At time t rrarr 570t2 - 320t 390t2 j gives the position

Question

At time t, r^→ = 5.70t² - (3.20t + 3.90t²) j gives the position of a 3.0 kg particle relative to the origin of an xy coordinate system ( r^→ is in meters and t is in seconds).

(a) Find the torque acting on the particle relative to the origin at the moment 8.01 s.

(b) Is the magnitude of the particle?s angular momentum relative to the origin increasing, decreasing, or unchanging?