Question

Two goods trains each 520 m long, are running in opposite directions on parallel tracks. their speeds are 42 km/hr and 36 km/hr respectively. find the time taken by the slower train to cross the driver of the faster one ?

Answer 1

slower train has to covered a distance of 0.520km
speed=s1+s2
=42+36
=78
t=d/s
=0.520/78
=0.006667 hours ×3600
= 24 second

Answer 2

Answer:

The the time taken by the slower train to cross the driver of the faster one is 24 seconds.

Step-by-step explanation:

Given : Two goods trains each 520 m long, are running in opposite directions on parallel tracks. Their speeds are 42 km/hr and 36 km/hr respectively.

To find : The time taken by the slower train to cross the driver of the faster one ?

Solution :    

Speed of train are 42 km/hr and 36 km/hr.

Relative speed of the train is 42+36=78 km/hr.

Convert km/hr into m/s,

$78\text{ km/hr}=78\times\frac{5}{18}=21.6\text{ m/s}$

Distance is 520 m.

Time taken is

$\text{Time}=\frac{\text{Distance}}{\text{Speed}}$

$\text{Time}=\frac{520}{21.66}$

$\text{Time}=24$

Therefore, The the time taken by the slower train to cross the driver of the faster one is 24 seconds.