Question

A vehicle starts off from rest and reaches a velocity of 80 km/h in 12 seconds. If the velocity increases uniformly, how far will the train travel in the first 12 seconds

Answer 1

Final speed v = 80 km/h = 80*(1000/3600) = 22.222... m/s.
Under uniform acceleration from rest, average speed = (0 + v)/2 = 11.111... m/s.
Distance = average speed × time = 11.111... × 12 = 133.333... m.

So the train travels 133.33 m (or 2/15 km) in the first 12 s.