Ques:- A train 270 meters long is moving at a speed of 25 km/hr. It will cross a man coming from the opposite direction at a speed of 2 km per hour is
A. 24 seconds
B. 28 seconds
C. 32 seconds
D. 36 seconds
Right Answer:
We are given:
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Length of train = 270 meters
-
Speed of train = 25 km/hr
-
Speed of man = 2 km/hr (coming from the opposite direction)
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We are to find: Time taken by the train to cross the man
🧠Concept:
When two objects move toward each other, their relative speed = sum of their speeds.
Also, time = distance / speed
🔄 Step 1: Convert speeds to m/s
To convert km/hr to m/s, multiply by 5/18:
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Train’s speed = 25 × 5/18 = 125/18 m/s
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Man’s speed = 2 × 5/18 = 10/18 m/s
Relative speed = (125 + 10) / 18 = 135 / 18 = 7.5 m/s
🔢 Step 2: Use formula to find time
Time=DistanceRelative Speed=2707.5=36 seconds\text{Time} = \frac{\text{Distance}}{\text{Relative Speed}} = \frac{270}{7.5} = 36 \text{ seconds}
âś… Final Answer:
The train will cross the man in 36 seconds.