Change set

Pick exam & year, then Go.

Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q1 (CISF/2023) Science & Technology › Basic Science (Physics, Chemistry, Biology)

Two trains are approaching each other on parallel tracks. Their lengths are 700 m and 400 m, respectively. The speed of the first train is 95 km/hr and that of the second train is 125 km/hr. The time required by the trains to cross each other is :

Explanation

To find the time required for the trains to cross each other, we use the concept of relative speed and total distance.

  • Total Distance: When two trains cross each other, the total distance to be covered is the sum of their individual lengths.
    Total Distance (D) = 700 m + 400 m = 1100 m.
  • Relative Speed: Since the trains are approaching each other (moving in opposite directions), their relative speed is the sum of their individual speeds.
    Relative Speed (S) = 95 km/hr + 125 km/hr = 220 km/hr.
  • Unit Conversion: To match the units of distance (meters), convert the speed from km/hr to m/s by multiplying by 5/18.
    S = 220 × (5/18) m/s = 1100/18 m/s.
  • Time Calculation: Time = Distance ÷ Speed
    Time = 1100 ÷ (1100/18) = 1100 × (18/1100) = 18 seconds.

Therefore, the time required by the trains to cross each other is 18 seconds.

✓ Thank you! We'll review this.

SIMILAR QUESTIONS

IAS · 1998 · Q138 Relevance score: 3.48

One local and another express train were proceeding in the same direction on parallel tracks at 29 km/hour and 65 km/hour respectively. The driver of the former noticed that it took exactly 16 seconds for the faster train to pass by him. What is the length of the faster train?

IAS · 2004 · Q104 Relevance score: 1.31

A and B start from the same point and in the same direction at 7 a.m. to walk around a rectangular field 400 m x 300 m. A and B walk at the rate of 3 km/hr and 2.5 km/hr respectively. How many times shall they cross each other if they continue to walk till 12 : 30 p.m?

CDS-I · 2004 · Q107 Relevance score: 1.20

Two men are standing on opposite ends of a bridge of 1200 metres long. If they walk towards each other at the rate of 5 m/minute and 10 m/ minute respectively, in how much time will they meet each other?

CAPF · 2024 · Q68 Relevance score: 1.05

A train travelling at a speed of 60 km/hr crosses a platform in 20 seconds. The same train crosses a person who is walking at a speed of 6 km/hr in the same direction as that of the train in 12 seconds. What is the length of the train and that of the platform, respectively?

CAPF · 2025 · Q66 Relevance score: 1.03

Two trains $A$ and $B$ are entering a railway platform from opposite direction. The length of the platform is 300 m. The speed of $B$ is two times the speed of $A$. The time taken by $B$ to cross the platform is one-third of the time taken by $A$ to cross the platform. If the sum of the lengths of $A$ and $B$ is 500 m, what is the difference in their lengths?