In the park, a mom pushes tangentially on a hand-driven merry-go-round and is able to accelerate it from rest to a frequency of 15 rpm in 12.0 s. Assume the merry-go-round is a uniform disk of radius 2.0 m and has a mass of 900 kg, and two children (each with a mass of 20 kg) sit opposite each other on the edge. Calculate the torque required to produce the acceleration, neglecting frictional torque.