Question
A train 200 m long passes a man standing on a platform
in 10 seconds and passes the platform completely in 30 seconds. Find: (a) the speed of the train in km/h, (b) the length of the platform.Solution
(a) Speed of train: Speed = distance / time when passing man = 200 / 10 = 20 m/s In km/h: 20 × (18/5) = 72 km/h (b) When passing platform, distance = train length + platform length = 200 + L Time = 30 s ⇒ 20 × 30 = 200 + L 600 = 200 + L ⇒ L = 400 m Answer: Speed = 72 km/h, platform length = 400 m.
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