A wheel with radius 1.50 m is turning about a horizontal axis through its center (the plane of the wheel is vertical). The wheel starts from rest and undergoes constant angular acceleration in the counter clockwise direction. Point A starts at the highest point on the wheel at t=0. After 3.50 seconds the angular speed of point A is equal to 4.50 rad/s. What are the direction and magnitudes of point A's linear acceleration when it is?
1) At the lowest point of its trajectory after making half of a revolution?
2) At the left-most point of its trajectory after making a quarter of a revolution?
3) How much time does it take for the wheel to complete the first revolution?