Question

11. Two trains each of length 150 m are moving in opposite direction at 36 km/hr and 72 km/hr respectively. Time taken by them to just cross each other completely is
(1) 4s
(2) 6s
(3) 8s
(4) 10s​

Answer 1

this helps you it is right answer

Answer 2

Answer:

The time taken by them to just cross each other completely is 10 s.

Explanation:

Speed of the one train= 36 km/hr

Speed of the second train= 72 km/hr

Therefore, the relative speed of the two trains = Speed 1 + Speed 2 ( as both the travelling in the opposite direction)

Relative speed= 108 km/hr

Now, converting this to 'm/s' as we want the time in 's',

108 km/hr = 108×( 5/18 ) m/s = 30 m/s

The time required to cross each other= Total distance/Relative Speed

So, Time= ( 150+150)/ 30 s

So, Time = 10 s.

Therefore, the time taken by the two trains to just cross each other completely is 10 s.