Find the length of the bridge, which a train 120 m long travelling at 54 kmph can cross in 30 seconds.
Answer & explanation
Correct answer: option 3
Speed = \(\frac{ Distance}{ Time}\)
Let the length of the bridge be x
54 x \(\frac{5 }{18 }\) = \(\frac{120 + x}{ 30}\)
15 = \(\frac{120 + x}{ 30}\)
15 x 30 = 120 + x
x = 450 - 120
x = 330 m
Thus, the length of the bridge is 330 m