If a train crosses a pole in 12 seconds while travelling at a speed of 45km/hr, then in how much time will the train cross a bridge of length 600m at same speed?
Answer & explanation
Correct answer: option 2
Speed = \(\frac{Distance }{Time }\)
let the length of train be x
45 x \(\frac{ 5}{ 18}\) = \(\frac{ x}{ 12}\)
\(\frac{ 25}{ 2}\) = \(\frac{ x}{ 12}\)
x = 150 m
Now,
45 x \(\frac{ 5}{ 18}\) = \(\frac{\text{150 + 600}}{Time}\)
\(\frac{ 25}{ 2}\) = \(\frac{\text{750}}{Time}\)
Time = 60 seconds