A bus start from rest with a uniform acceleration of 4m/s for the first 5second. It then accelerate at a uniform rate of 2m/second square for another 10secons. It continues at a constant speed for 15second and finally comes to rest by uniform retardation. sketch the velocity time graph for this motion, from your graph, calculate:

1: total distance travelled
2:average speed for the whole journey
3:average retardation as the body is brought to rest
4:the maximum speed attained during the motion.