Tony is picked up by an ambulance, which moves in a straight line with position given by s(t)=2t^3 - 9t^2 + 12t - 5 metres, where t is the time in seconds. Determine the time intervals where the ambulance's speed is increasing
v(t) = 6t^2 - 18t + 12
v ' (t) = 12t - 18
the ambulance's speed is increasing when the derivative of the speed is positive
12t- 18 > 0
12t > 18
t > 3/2