Two rifles are fired from the same place at a difference of 11 minutes 45 seconds. But a man who is coming towards the place in a train hears the second sound after 11 minutes. Find the speed of train. (speed of sound = 330 m/s)

Question

নিচের অপশন গুলা দেখুন

• 108 kmph
• 36 kmph
• 81 kmph
• 72 kmph

Answer 1

সঠিক উত্তর হচ্ছে: 81 kmph

ব্যাখ্যা: Distance travelled by man-train in 11 minute = distance traveled by sound in (11 min 45 sec - 11 min) = 45 sec.
Let the speed of train be x kmph.
Now,
Or, x × 11/60=45/3600×330×18/5
Or, x = 81 kmph.