1. A train travels along a straight horizontal track between two stations, \(A\) and \(B\).

In a model of the motion, the train starts from rest at \(A\) and moves with constant acceleration \(0.3 \mathrm {~m} \mathrm {~s} ^ { - 2 }\) for 80 s .
The train then moves at constant velocity before it moves with a constant deceleration of \(0.5 \mathrm {~m} \mathrm {~s} ^ { - 2 }\), coming to rest at \(B\).

1. For this model of the motion of the train between \(A\) and \(B\),
   1. state the value of the constant velocity of the train,
   2. state the time for which the train is decelerating,
   3. sketch a velocity-time graph. The total distance between the two stations is 4800 m .
2. Using the model, find the total time taken by the train to travel from \(A\) to \(B\).
3. Suggest one improvement that could be made to the model of the motion of the train from \(A\) to \(B\) in order to make the model more realistic.