Question

2 trains, each 100 m long, pass each other on parallel tracks. If they are moving in the same direction, the faster one takes 2 minutes to pass the slower one completely. If they are moving in opposite direction, they completely pass each other in 6 seconds. Find the speed of the slower train.​

Answer 1

Step-by-step explanation:

Let the speed of the faster train be x km/hr and that of the slower train be y km/hr.

Relative speed when both move in same direction =(x−y) km/hr

Relative speed when both move in opposite direction =(x+y) km/hr Total distance travelled = Sum of lengths of both the trains =200 m

Given,

(x−y)×

18

5

200

=60 and

(x−y)×

18

5

200

=10

⇒

5(x−y)

3600

=60 and

5(x+y)

3600

=10

⇒x−y=

300

3600

=12 ....(i)

and x+y=

50

3600

=72 ....(ii)

Adding eqn (i) and eqn (ii), we get

2x=84

⇒x=42 km/hr

∴ From (i), y=30 km/hr

Answer 2

Answer:

30km/h

Step-by-step explanation:

According to the question, Each train is 100 meters long. ⇒ y = ( 50/6 × 18/5 ) km/h = 30 km/h ( Since, 1 m/s = 18/5 km/h ),

So, the speed of slower train is 30 km/h