A pulley with a rotational interia of 4.4*10^-3 kg m^2 about its axle and a radius of 6 cm is acted on by a force applied tangentially at its rim. The force magnitude varies in time as F=0.32t + 0.27t^2 where F is in newtons if t is given in seconds. The pulley is initially at rest. At t=3.9s what is the angular velocity?