THE PROBLEM On a hot day, you have started a fan blowing air directly on you at ar-43 rpmj. After t=14 seconds you increase the angular speed and turn the fan by 90 degrees, giving (or=55 rpm 1 . Calculate the average angular acceleration (magnitude and direction). PAPER SOLUTION ▼ INTERPRET Identify the true statement. The average angular acceleration will be A. in the negative i direction. OB. at some angle in between the positive i and positive j directions. C. in the positive i direction. D. in the positive j direction. E. at some angle in between the positive i and negative j directions. O None of the above. ▼ DEVELOP In your answers below, type wi and wf to represent a, and ω- Derive an algebraic expression for the magnitude of the average acceleration. α= Derive an algebraic expression for the direction of the average acceleration (counterclockwise from i as usual). θ= EVALUATE ASSESS