Here is the fulll question, I omitted part a) because I did that already...
A car starts from rest at traffic lights and moves in a stragiht line. The car moves with constant acceleration 3m/s² until is it is moving with speed 9m/s. It then moves for 5s with an acceleration of 2m/s² before moving at a constant speed.
a) Calculate the constant speed reached by the car.
Given that the car is still moving at this constant speed 12s after leaving the traffic lights,
d)calculate the distance travelled in 12s.