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A vertical wheel with a diameter of 50 cm starts from rest and rotates with a constant angular acceleration of 7.5 rad/sZ around a fixed axis through its center counterclockwise. a. Where is the point that is initially at the bottom of the wheel at t : 8 5? Express your answer as an angle in radians between 0 and 27r, relative to the positive x axis. 0f : o\" 5.951 radians b. What is the point's tangential acceleration at this instant? a : 0\" 1.875 m/s2