At time t = 0, a 2.10 kg particle has position vector 7 = (3.00 m )i - (5.00 m ) j relative to the origin. Its velocity is given by U = ( - 1.2312 m/s ) i fort in seconds. About the origin with t = 18.6 s, what are (a) the particle's angular momentum and (b) the torque acting on the particle, both in unit-vector notation? (a) Number Units kg-m^2/s (b) Number i Units N.m