Physics
posted by Bell .
A merrygoround in the park has a radius of 1.8 m and a rotational inertia of 900 kgm^2. A child pushes the merrygoround with a constant force of 80 N applied at the edge and parallel to the edge. A frictional torque of 12 Nm acts at the axle of the merrygoround.
a. What is the net torque acting on the merygoround about its axle?
b. What is the rotational acceleration of the merrygoround?
c. At this rate, what will the rotational velocity of the merrygoround be after 15s if it starts from rest?
d. What is the rotational acceleration of the merrygoround if the child stops pushing after 15 s.? How long will it take for the merrygoround to stop turning?

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