Question

Two trains 115 m and 135 m long are running along parallel tracks at the speeds of 35km/h and 45km/h respectively . how long will they take to pass by each other if they run 1, in opposite direction (Ans-11.25s) 2, in the same direction (ans-1min30sec) ......

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Answer 1

Step-by-step explanation:

Given :- speed of trains = 35,45

=> length of trains => 115 ,135

Solution:-

case 1> opposite direction

=> here relative speed will be => 45+35 =>80km/h

=> now time = total distance/ speed

=> 115+135/80

=> 250/80×18/5

=> 50×18/80 = 11.25 second

=> Case 2. same direction

=> here relative speed => 45-35 = 10Km/h

=> 250/10×18/5

=> 50×18/10 => 900/10 = 90 second

Answer 2

$\bf{\underline{Question:-}}$

Two trains 115 m and 135 m long are running along parallel tracks at the speeds of 35km/h and 45km/h respectively . how long will they take to pass by each other if they run 1, in opposite direction, in the same direction.....

$\bf{\underline{Solution:-}}$

• → in same direction

→ total length of train = 115 + 135 = 250m

→ relative speed=45 - 35 = 10km/h

• in meter per second = 10 x 5/18
• in m/sec = 50/18 = 25/9

→ time taken = 250/25/9

→ time taken = 250x9/25

→ time taken = 10x9=90 sec

→ 90 sec in min =1 min 30sec

_______________________

• → in opposite directions

→ length of train = 250m

→ relative speed = 45 + 35 = 80 km/h

→ in m/s = 80 x 5/18 = 200/9 m/s

→ time taken = 250/200/9

→ time take = 250 x 9/200

→ time taken = 11.25sec

_______________________

$\bf{\underline{Hence:-}}$

• 1st answer is 1 min 30 sec
• 2nd answer is 11 min 25 sec