A bus is travelling at 15 m/s. It maintains this speed for 6 s and then comes to rest with uniform retardation in the next 4 s.
(i) Sketch the velocity–time graph for the complete 10 s period.
(ii) Determine the magnitude of retardation during the last 4 s from the graph.
(iii) Find the total distance covered by the bus in 10 s by calculating the area under the graph.
(iv) Compute the average speed of the bus for the whole journey and state whether it is greater than, less than, or equal to 15 m/s, giving reasons based on your graph.