A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
40 sec
42 sec
45 sec
48 sec
Explanation:
| Formula for converting from km/hr to m/s: $x$ km/hr =$ \left(x \times\dfrac{5}{18} \right) $m/s. |
| Therefore, Speed =$ \left(45 \times\dfrac{5}{18} \right) $m/sec=$ \dfrac{25}{2} $m/sec. |
Total distance to be covered = (360 + 140) m = 500 m.
| $\therefore$ Required time =$ \left(\dfrac{500 \times 2}{25} \right) $sec= 40 sec. |