Question

a a person sitting in a train travelling at a speed of 72 km per hour is crossed by another train in the opposite direction in 15 second then find the speed of the second train in kilometre per hour
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Answer 1

Answer:

54 km /h

Step-by-step explanation:

Given :

A person sitting in a train travelling at a speed of 72 km/h, another train of length 525 m cross it in 15 seconds.

Formula used :

Time = Distance/Speed

Calculations :

Let the speed of the second train be 'S' km/h

Speed of first train in m/s = 72 × (5/18)

⇒ 20 m/s

Now, according to the question

15 = 525/(20 + S) (Distance covered will be length of second train as it crosses the man sitting on the train in 15 seconds)

⇒ 300 + 15S = 525

⇒ 15S = 225

⇒ S = 15 m/s

Now speed in km/h = 15 × (18/5)

⇒ 54 km/h

∴ The speed of the train will be 54 km/h