Question

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

Answer 1

Answer:

Train will travel 625km before it is brought to rest.

Explanation:

Let the initial speed of the train be $u = 90km/h \\ = 25m/s$

Final speed of the train,

$v = 0 \: (train \: comes \: to \: rest)$

Acceleration, $a = 0.5m {s}^{ - 2}$

As per ${3}^{rd}$ law of motion,

${v}^{2} = {u}^{2} + 2as \\ (0 {)}^{2} = (25 {)}^{2} + 2(0.5)s \\ s = train \: travelled \: distance \\ ∴s = \frac{(25 {)}^{2} }{2(0.5)} = 625km$

Train will travel 625km before it is brought to rest.