SOLUTION: two trains ,each 80m long passes each other on parallel lines.If they are going in the same direction,the faster train takes one minute to pass the other completely.If they are goi

Algebra ->  Equations -> SOLUTION: two trains ,each 80m long passes each other on parallel lines.If they are going in the same direction,the faster train takes one minute to pass the other completely.If they are goi      Log On


   

Question 42419: two trains ,each 80m long passes each other on parallel lines.If they are going in the same direction,the faster train takes one minute to pass the other completely.If they are going in opposite directions,they overtake each other in 3 seconds.find the rate of each train in metre per second.
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the speed of one train and x+1 min --> x+60 be the speed of the other train on parallel track.
EQUATION:
80%2Fx-80%2F%28x%2B1%29=3
80[(x+60)-(x)]=3[(x+60)(x)]
4800=3%28x%5E2%2B60x%29
x%5E2%2B60x-1600=0
x+=+%28-60+%2B-+sqrt%28+60%5E2-4%2A1%2A-1600+%29%29%2F%282%2A1%29+
x=20
20+60=80
Hence, the speed of one train is 20m/s and the speed of the other is 80m/s.
Paul.