A train comes to a stop in 3 minutes. if the train had a uniform acceleration of -3.5 m/s/s what was initial velocity of the the train?

initial velocity of the train is ##630 ms^-1##
Given the formula of , ##a = (v – u)/t##
So firstly, what we have to do is we have to list down all the known information. Therefore, we should get…
##a = – 3.5ms^-2##
##t = 3 min * 60 s = 180 s## (S.I unit of ##t## is seconds ##s##)
##v = 0 ms^-1## (Because the train stops after the 3 minutes, therefore, its final velocity is zero)
After we list down all the necessary information, substitute the given variables into the formula.
Since ##a = (v – u)/t##, thus,
##-3.5 ms^-2 = (0 ms^-1 -u)/(180s)##
##(0 ms^-1 -u) = -3.5ms^-2 * 180s##
##(0 ms^-1 – u) = -630 ms^-1##
## 0 – u = -630##
## – u = -630 – 0##
## :. u = 630ms^-1##
Therefore, initial velocity of the train is ##630 ms^-1##