CBSE Class 9 Answered

Consider system to be ideal one.Let two trains have equal masses m.Let the train with velocity has a speed of magnitude v.

By conservation of momentum,

mv=2mv'

or v'=v/2

So if the system would have been ideal this should have happened.

But in real life situation the velocity transfer does not take place and both the trains experience an impuslse which

can crudely be approximated as mv/2 and mv/2.The huge impulses lead to a huge damage specially to bogeys which collode and in that order.