Calculate the magnitude of the torque acting about the origin on the particle.

A particle of mass 2kg located at the position vector r = (3?2)/2 (ˆi – ˆj) has an acceleration a = 5/3(2ˆi + 2ˆj + kˆ) acting on it where the unit of r is the meter the units of acceleration are m/s2. Calculate the magnitude of the torque acting about the origin on the particle.