A train starts from rest and accelerates uniformly, until it has traveled 3.7 km and acquired a velocity of What is the acceleration of the train during this time?
The train's average acceleration during this time is
(7.4 km) / (the time taken)² .
The final velocity is not given in the question ... there's a place for it, but the number disappeared. In order to answer the question, we need to know either the final velocity or else the time taken by the story.