#### Question

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.

#### Solution

Initial speed of the train, *u* = 90 km/h = 25 m/s

Final speed of the train, *v *= 0 (finally the train comes to rest)

Acceleration = −0.5 m s^{−2}

According to third equation of motion:

*v*^{2} = *u*^{2} + 2 *as*

(0)^{2} = (25)^{2} + 2 (−0.5) s

Where,* s* is the distance covered by the train

`s=25^2/(2(0.5))=625m`

The train will cover a distance of 625 m before it comes to rest.

Is there an error in this question or solution?

Solution 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) Concept: Equations of Motion by Graphical Method - Equation for Position-time Relation.