An electric ceiling fan is rotating about a fixed axis with an initial angular velocity magnitude of 0.290 rev/s. The magnitude of the angular acceleration is 0.909 rev/s². Both the the angular velocity and angular accleration are directed counterclockwise. The electric ceiling fan blades form a circle of diameter 0.750 m.
a. Calculate the magnitude ar of the radial (or centripetal) acceleration of the point at the end of the fan blade.