1. 16 A mass of 1.5 kg attached to a light string of length 60 cm is made to rotate from rest to an angular velocity of 30 rads-1 in a time of 4.5 s. a Calculate the final angular momentum of the mass on the string. [2] b. Calculate the kinetic energy gained by the mass. [1] C. Calculate the torque required to make the mass rotate at this angular velocity. [1]