A wheel starts from rest and accelerates uniformly at 4 rad/s2 for 5 seconds. It then continues at a constant angular velocity for an additional 10 seconds. After this time, it decelerates at 2 rad/s2 until it comes to rest. The radius of the wheel is 0.5m

a. What is the angular velocity of the wheel after 5 seconds? b. What is the total angular displacement of the wheel during the first 15 seconds? c. What is the final angular velocity of the wheel after 15 seconds? d. How many revolutions did the wheel make during the entire motion?