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


Initial speed, u = 90 km/h2

=


= 25 m/s


Final speed, v = 0 (As the train stops)


Acceleration, a = -0.5 m/s2


And,


Distance travelled, s =?


Now, v2 = u2 + 2as


(0)2 = (25)2 + 2 × (-0.5) × s


0 = 625 – 1 × s


s = 625 m


Therefore, 625 metres is the distance travelled by the train before it is brought to rest.


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