A merry-go-round in the park has a radius of 1.8 m and a rotational inertia of 900kgm^2. A child pushes the merry-go-round with a constant force of 80 N applied at the edges and parallel to the edge. A frictional torque of 12 Nm acts at the axle of the merry-go-round.
a. what is the net torque acting on the merry-go-round about its axle?
b. what is the rotational acceleration of the merry-go-round?