The trains take <u>57.4 s</u> to pass each other.
Two trains A and B move towards each other. Let A move along the positive x axis and B along the negative x axis.
therefore,

The relative velocity of the train A with respect to B is given by,

If the train B is assumed to be at rest, the train A would appear to move towards it with a speed of 170 km/h.
The trains are a distance d = 2.71 km apart.
Since speed is the distance traveled per unit time, the time taken by the trains to cross each other is given by,

Substitute 2.71 km for d and 170 km/h for 

Express the time in seconds.

Thus, the trains cross each other in <u>57.4 s</u>.
The answer is 60 km. I hope it helps i dont know if this is right or wrong.
How many atoms are in something determines it "mass"
Ernest Rutherford is the answer you are looking for my friend.
Answer:
Both eggs are identical. The aim is to find out the highest floor from which an egg will not break when dropped out of a window from that floor. If an egg is dropped and does not break, it is undamaged and can be dropped again. However, once an egg is broken, that's it for that egg.