Discussion Forum

The length of the bridge,which a train 130 metres long and travelling at 45 km / hr can cross in 30 seconds, is :

Answer:

Explanation:

Speed $=\left(45\times\frac{5}{18}\right)$ m/sec $=\left(\frac{25}{2}\right)$ m/sec; Time $=30$ sec.

Let the length of bridge be $x$ metres.

Then, $\frac{130+x}{30}$ $=\frac{25}{2}$

$\Leftrightarrow 2(130+x)$ $=750$ $\Leftrightarrow x=245$ m.