A wheel with radius 1.50 m rotate about a horizontal axis through its center (plane of wheel is vertical). the wheel starts from rest and undergoes constant angular acceleration counterclockwise. Point A starts at the highest point on the wheel t=0. After 3.50 s the angular speed of point A is equal to 4.50 rad/s. What are the magnitudes and direction of point A’s linear acceleration when it is
a.) at the left most point of its trajectory after making a quarter of a revolution.
b.) at the lowest point of its trajectory after making half of a revolution.
c.) how much time does it take to complete the first revolution.