A train crosses a platform 180 m long in 60 sec at a speed of 72 km/h. The time taken by the train to cross an electric pole is:

Question

নিচের অপশন গুলা দেখুন

• 51 sec
• 0.51 min
• 5.1 sec
• 5.1 min

Answer 1

সঠিক উত্তর হচ্ছে: 51 sec

ব্যাখ্যা: Let the length of the train be x meter. And length of the platform is 180.
Speed of train = 72 × 5/18 = 20 m/sec
As we know,
Speed = Distance/Time
20 = (180 + x)/60
⇒ 1200 = 180 + x
⇒ x = 1200 – 180 = 1020
∴ Required time to cross poll by train = 1020/20 = 51 sec