A boy runs opposite to that of train at a speed of 20 km/hr. If the relative speed between train and the boy running in opposite direction is 50 km/hr. What is the length of train, if it takes 20 seconds to cross the boy, when he is at rest?

Question

নিচের অপশন গুলা দেখুন

• 154.12 m
• 160.23 m
• 166.6 m
• 159.1 m

Answer 1

সঠিক উত্তর হচ্ছে: 166.6 m

ব্যাখ্যা:

Speed =Distance/Time
Relative speed = Speed of train + Speed of boy
50 = Speed of train + 20
So, Speed of train = 50–20 = 30 km/hr
Convert km/hr into m/s
30 km/hr = 30x(5/18) = 8.33 m/s
Distance
= Speed x Time
= 8.33 x20
= 166.6 m