Aspinning wheel on a fireworks display is initially rotating in a counterclockwise direction. the wheel has an angular acceleration of -7.80 rad/s2. because of this acceleration, the angular velocity of the wheel changes from its initial value to a final value of -22.4 rad/s. while this change occurs, the angular displacement of the wheel is zero. (note the similarity to that of a ball being thrown vertically upward, coming to a momentary halt, and then falling downward to its initial position.) find the time required for the change in the angular velocity to occur.