29see first convert feet into metres.. i guess 3 feet = 0.9m
and miles into km/hr and then m/s
1 mile = 1.6 km
so the train is at 96km/hr or 26m/s
now time taken to achieve top speed with a = 0.9m/s2
t≈ 30 seconds
now we have
s = 1/2 a t2
so s ≈ 400m
so the same distance will be covered during retardation
so the distance which the train travels at constant velocity = 9.2 km
time taken to travel it 350 seconds
so total time 350 + 30 + 30 = 410 ≈ 400 seconds..
PS : i manually calculated the abv values..so there may be some error ± 5% in the calculalations..