A railway convoy measuring 240 m in length clears a telegraph pole in 24 seconds. How much duration will it need to traverse a 650 m long station platform?
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Answer: B. 89 Sec
Explanation
Dividing the train length of two40 meters by its pole clearance time of twenty-four seconds gives a speed of ten meters per second. To clear a platform completely, a train must travel a distance equal to the sum of its own length plus the platform length. Adding two hundred forty meters and six hundred fifty meters gives a total distance of eight hundred ninety meters, which takes eighty-nine seconds at ten meters per second. Train crossing problems require accounting for the physical length of the train when calculating clearance distances. Speed equals total distance divided by elapsed time according to standard kinematic motion equations. Clearing a static object like a pole involves a distance equal to the train's own length alone.
Option A suggests eighty seconds, which accounts only for the platform length while forgetting to add the train length. Option C proposes ninety seconds, overestimating the total duration due to a slight arithmetic rounding error. Option D offers ninety-five seconds, failing to match the exact division result of eight hundred ninety by ten.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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