Iwill mark ! a motorcycle is moving at a constant velocity of 15 meters/second. then it starts to accelerate and reaches a velocity of 24 meters/second in 3 seconds. what’s the acceleration of the motorcycle over this time? use . a. 9 m/s2 b. 8 m/s2 c. 6 m/s2 d. 5 m/s2 e. 3 m/s2