A particle is moving in a straight line according to the position function

s(t) = t³ - 6t² + 9t + 5, t 0, where s is measured in metres and t in seconds. a) Find the average acceleration in the first 3 seconds. b) The particle changes direction twice. When does that happen? c) How far away, from the starting point, is the particle at t = 3? d) The particle brakes once. When does that happen? e) Find the total distance travelled before braking occurs.