Question

When two trains were running in same direction at 90 km/hr and 70km/hr then faster train passed a man sitting in slower train in 36 sec . Find length of faster train?

Answer 1

As Trains are moving in same direction,  

So, Relative Speed = 90-70 = 20 kmph

= 20*(5/18) = 50/9 m/sec

Length of Train= Speed * Time

Length=509∗36=IS UR ANSWER

HOPE THIS HELPZ

NAZ:):)

THANK U

Answer 2

In the question, Velocities of two trains were given as a reference to earth.

In order to solve this question, we have to find the velocity of the fast moving train with reference to the slow moving train.

$V_{FastTrain, Slow Train} = V_{FastTrain, Earth} +V_{Earth, Slow Train}\\V_{FastTrain, Slow Train} = V_{FastTrain, Earth} - V_{Slow Train,Earth} \\\\V_{FastTrain, Slow Train} =90 - 70\\\\V_{FastTrain, Slow Train}= 20 kmh^{-1} \\V_{FastTrain, Slow Train}= 20 X 18/5 = 72ms^{-1}$

Then we can find the length of the fast moving train by,

36 X $V_{FastTrain, Slow Train}$

36 X 72

Answer is 2592m