A gun is fired from behind a train and the driver hears the sound 1 min 30 sec later than the guard. Find the length of train if the speed of train and sound are 60 km/hr and 1100 m/min .
Answer & explanation
Correct answer: option 3
Speed of train = 60 km/hr = 1000 m/min
Speed of sound = 1100 m/min
As train and bullet both moves in same direction .
So, relative speed = ( 1100 - 1000 ) = 100 m/min
Time taken by sound to travel through the length of train = 1 min 30 sec
= \(\frac{3}{2}\) min
Distance = Speed × Time
= 100 × \(\frac{3}{2}\) = 150 m
So , length of train = 150 m