Question

A train is travelling at a speed of 90km/h-¹ brakes are applied so as produce a uniform acceleration of -0.5m s-² . find how far the train will go before it is brought to rest

Answer 1

we use

90kmph=90*5/18=25

v²-u²=2as

0-25²=2(-0.5)(s)

-625/-1=s

625m=s

The train travels 625km before going to rest .

Answer 2

Initial speed(u) = 90km/hr or 25m/s
retardation(a) = -0.5m/s²
final speed(v) = 0

we have to find distance travelled say "s"

so we will use
v²-u²=2as
so plug in the values you will get
0-(25)²=2(-0.5)(s)
= -625 = -s
=> s = 625m