A car travels on a straight road where east is taken as the positive direction. It covers 120m eastward in 8s, immediately turns back, and then travels 30m westward in 4s. Answer all parts clearly, showing every step.
(i) Calculate the total distance travelled by the car.
(ii) Find the displacement of the car from its starting point after the complete journey.
(iii) Determine the average speed for the entire journey.
(iv) Determine the magnitude and direction of the average velocity for the whole journey.