Explanation:
you made an error while putting the unit of velocity
acceleration = change in vel in time
a = (∆v/t)
the initial vel (u) =0m/s
the final vel (v) = 5,500m/s
time (t) = 8min + 30sec = 480 + 30
510s
a = (5,500 - 0)/510
5,500/510
a = 10.78m/s²
