### Q.:- A train is travelling at a speed of 90 kmh^{-1}. Brakes are applied so as to produce a uniform acceleration of -0.5 ms^{-2}. Find how far the train will go before it is brought to rest?

*Answer:-*

Here, initial speed, u = 90 kmh-1 = 90 x(5/18) = 25 ms-1

Acceleration, a = – 0.5 ms-2

Train brought to rest, so final speed, v = 0

From third equation of motion, v2 = u2 + 2as

0 = (25)2 + 2 x 0.5 x s

0 = 625 – s

s = 625 m