The train travels between cities A and B which are 180km far away from each other, in 1 hour. During this travel, the train keeps its speed constant for 4 minutes as 120 km/h. During the last 6 minutes before arriving at city B, the train decelerates and travels with an average speed of 100km/h . Excluding the time when the train travels with a constant speed and the time it decelerates, determine the average velocity of the train. 2–2.8 While traveling along a straight track, the motorcyclist passes from the starting point 0. The position of the motor is defined by the function?