Question
Train 'Express Star' is moving at a speed of 90 km/hr,
traveling towards train 'Speedy Voyager,' which is twice as long as 'Express Star' and has the same speed as 'Express Star.' When these two trains travel in opposite directions, they pass each other in 30 seconds. Find the time it takes for 'Express Star' to pass a stationary pole.Solution
ATQ, Speed of Train 'Express Star' = Speed of 'Speedy Voyager' = 90 km/hr = [90 Ă(5/18)m/s] = 25 m/s Let, the length of Train 'Express Star' = 'L' metres So, length of 'Speedy Voyager' = 2 Ă L = '2L' metres ATQ, {(L+2L)/(25+25)} = 30 Or,(3L/50)= 30 So, L = 500 So, time taken by 'Express Star' to cross a stationary pole.= (500/25) = 20 Seconds
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I...