Question

Two identical trains take 3 sec to pass one aother when going in opp direction but takes only 2.5 sec if the speed of one is increased by 50% the time one would take to pass the other going in same direction at their original speed

Answer 1

Answer:

let train A is moving along positie x axis with vel = +V

train B along negative x axis = -U

vel of train A with respect B is = V-(-U) = V+U

let S be distance

S=(V+U)3

S=(V + U + U/2)2.5

=> S= (V+3/2U)2.5

get v and u in terms of S

then apply S=(V-U)t (now V along and u in same direction v=V-U)

and find t

may be answer 30/4 secs