Correct Answer: 10.8
Explanation:
Step 1: Understand what's given
Step 2: Use relative speed
Since they are moving in opposite directions, we add their speeds:
Relative speed = 60 + 40 = 100 km/h Convert km/h to m/s: 100 × (1000 / 3600) = 100 × 5/18 = 27.78 m/s
Step 3: Total distance to be covered
They will completely cross each other when they cover the sum of their lengths:
Total distance = 140 + 160 = 300 meters
Step 4: Calculate time
Time = Distance / Speed = 300 / 27.78 ≈ 10.8 seconds
Answer: Approximately 10.8 seconds
Therefore, the two trains will take about 10.8 seconds to completely cross each other.
This is a typical question on trains involving relative speed. Always remember to:
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