Given, initial speed of the train, u=90 kmph=90×518=25 ms−1, final speed of the train, v=0 (Finally the train comes to rest)
and acceleration =−0.5 ms−2
Let s be the distance covered.
According to the third equation of motion, v2=u2+2as
(0)2=(25)2+(2×−0.5×s)
⇒s=2522×0.5=625 m