Keep getting the wrong solution, please help?

A lawn sprinkler has three spouts that spray water, each r = 13.0 cm long. As the water is sprayed, the sprinkler turns around in a circle. The sprinkler has a total moment of inertia of 8.65 10-2 kg � m^2. If the sprinkler starts from rest and takes 3.90 s to reach its final speed of 2.2 rev/s, what force does each spout exert on the sprinkler?____N