A wind turbine rotor rotates about its spin axis, and the rotor nacelle also rotates about the vertical to keep incoming wind parallel to the rotor spin axis. In addition, the rotor spin axis is tilted 10 deg upward. Consider three reference frames: the inertial frame I, the nacelle frame N, and the rotor-fixed frame B. The nacelle frame is oriented such the IN- IN plane is parallel to the , -, plane. The rotor rotates about ] at a time-varying rate @. Determine the angular acceleration of the turbine blades (or, equivalently, the rotor-fixed frame B) with respect to the ground-fixed inertial frame I. In our notation this is denoted as B/. Express your results in terms of N frame units vectors, and in terms of @, @2, and relevant trigonometric functions. [Hint: Consult the handout on addition of angular velocities. First compute the angular velocity of the rotor with respect to the I frame, then apply the definition of angular acceleration and the vector derivative transport theorem.] (12 points) N @2 @ KN K I JN 10 3.5 @ A B JN