Answer:
I believe the acceleration is 3.66666666667 m/s
Explanation:
Acceleration formula: a = vf - vi / t
Initial velocity: 0 (I believe it was 0, as it wasn't moving in the beginning)
Final velocity: 55 m/s
Time: 15 s
Substituting values: 3.66666666667 = 55 - 0 / 15