Find the length of the bridge, which a train 120 m long travelling at 54 kmph can cross in 30 seconds.

330 m

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