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The length of the bridge is 150m. The time of the whole train passing through the bridge is calculated as follows: (1) the time of the whole train passing through the bridge. (2) the time of the whole train passing through the bridge
(1) According to x = 12at2, the time for the train to arrive at the bridgehead from the beginning of movement: T1 = 2x1a = 2 × 2001s = 20s. The time for the train to leave the end of the bridge from the beginning of movement: T2 = 2x2a = 2 × (100 + 200 + 150) 1s = 30s. Then the time for the train to pass the whole bridge: T = t2-t1 = 10s. (2) the time for the train to arrive at the bridgehead: T3 = 2x3a = 2 × (200 + 100) 1s = 106s, then the time for the whole train to pass the bridgehead: t '= t 3-t1 ≈ 4.5s. A: (1) the time for the whole train to pass the bridge is. 10s & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; (2) the time for the whole train to pass the bridge is 4.5s
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