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The velocity of a train increases uniformly from 20 km-h-1 t o60 km-h-1 in 0.2 h the distance travelled by the train during this period is A) 0.2 km B) 0.4 km C) 0.6 km D) 1.2 km |
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Answer» 8 kmExplanation:As per the provided information in the given question, we have :Initial velocity (u) = 20 km/hFinal velocity (v) = 60 km/hTime taken (t) = 0.2 HWE are asked to calculate the distance travelled by the TRAIN during this period.Let us FIND out the acceleration first.➝ v = u + atv denotes FINAL velocityu denotes initial velocitya denotes accelerationt denotes time➝ 60 = 20 + 0.2a➝ 60 – 20 = 0.2a➝ 40 = 0.2a➝ 40 ÷ 0.2 = a➝ 200 km/h² = aNow, by using the third equation of motion,➝ v² – u² = 2asv denotes final velocityu denotes initial velocitya denotes accelerations denotes distance➝ (60)² – (20)² = 2 × 200 × s➝ 3600 – 400 = 400s➝ 3200 = 400s➝ 3200 ÷ 400 = s➝ 8 km = sNone of the options is correct. The distance travelled by the train during this period is 8 km. |
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