A 130 m long train is moving in up direction with speed 17 km/h. Another train of 120 m long is moving in down direction with speed 108 km/h. The time in which second train crosses the first train will be

Question

A 130 m long train is moving in up direction with speed 17 km/h. Another train of 120 m long is moving in down direction with speed 108 km/h. The time in which second train crosses the first train will be (A) 5 s (B) 10 s (C) 12 s (D) 15 s

Tardigrade Admin · Accepted Answer

Total distance covered by second train in crossing the first train

= 250 m

Velocity of second train w.r.t first train

= 20 m / s + 30 m / s = 50 m / s

∴

Time

= \frac{Distance}{Velocity}

= \frac{250}{50} = 5 s

Q. A 130m long train is moving in up direction with speed 17km/h. Another train of 120m long is moving in down direction with speed 108km/h. The time in which second train crosses the first train will be

5 s

10 s

12 s

15 s

Total distance covered by second train in crossing the first train =250m Velocity of second train w.r.t first train =20m/s+30m/s=50m/s ∴ Time = Velocity Distance​ =50250​=5s

Q. A $130 m$ long train is moving in up direction with speed $17 km / h$ . Another train of $120 m$ long is moving in down direction with speed $108 km / h$ . The time in which second train crosses the first train will be

Total distance covered by second train in crossing the first train $= 250 m$
Velocity of second train w.r.t first train
$= 20 m / s + 30 m / s = 50 m / s$
$∴$ Time $= \frac{Distance}{Velocity}$
$= \frac{250}{50} = 5 s$