If 200m and 150m long trains moving in the same direction at a speed of 40kmph and 45kmph, what is the time taken by the trains to cross each other.

• Relative speed = 5 kmph= 5000/3600 m/sec= 50/36 m/sec
  distance to be covered = 200+150=350 m
  Time taken = 350/(50/36)= 36*7 = 252 secs
• 13 years agoHelpfull: Yes(36) No(0)
• both train travelling in same direction,so relative speed is=(45-40)=5kmph
  5 kmph in m/s= 5*(5/18)=25/18 m/s
  
  distance traveled=sum of length of both trains
  D=200+150=350m
  
  speed=(distance traveled/time taken)
  i.e S=(D/t)
  therefore t=(D/S)
  t=350/(25/18)
  t=350*(18/25)
  t=252 sec......
  
• 13 years agoHelpfull: Yes(15) No(1)
• ANS= 252 seconds
  Here relative speed is 5 kmph. this means dat if train 1 is not moving,then the other train is moving at 5kmph. hence total distance is 200+150m. speed is 5000/3600 m/sec.
  hence time required is= 350/(5000/3600) secs=252 seconds
• 13 years agoHelpfull: Yes(6) No(0)
• distance=speed*time
  resultant dist=relativ speed*time
  350=5*(5/18)*t
  thios results in
  t=252 seconds=4.2 mins
• 13 years agoHelpfull: Yes(4) No(0)
• relative speed of the trains=(45-40)km/h=5km/h
  5*5/18=25/18 m/sec
  time taken to cross each other=200+150=350
  total time taken=350*18/25=252sec
• 9 years agoHelpfull: Yes(1) No(1)