A scooter starts from rest at a traffic signal, accelerates uniformly for 4s until it reaches a speed of 20ms−1, and then continues at this constant speed for the next 3s.
(i) Draw the velocity–time graph for the entire 7s interval.
(ii) Determine the magnitude of the scooter’s acceleration during the first 4s.
(iii) Calculate the total distance travelled by the scooter in the 7s.
(iv) Find the average speed of the scooter over the whole journey.