The length of the bridge which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds is:
200 m
225 m
245 m
250 m
Explanation:
| Speed =$ \left(45 \times\dfrac{5}{18} \right) $m/sec=$ \left(\dfrac{25}{2} \right) $m/sec. |
Time = 30 sec.
Let the length of bridge be $ x $ metres.
| Then,$ \dfrac{130 + x}{30} $=$ \dfrac{25}{2} $ |
$\Rightarrow$ 2$\left(130 + x\right)$ = 750
$\Rightarrow x $ = 245 m.