Given: Length of train = 125 m Length of bridge = 62.5 m Length of railway crossing = 75 m Time to cross the bridge by train = 6 seconds Formula Used: Distance = Speed × Time Calculation: Time to cross bridge = (Length of train + Length of bridge)/Speed of train ⇒ 6 = (125 + 62.5)/Speed of train ⇒ Speed of train =
187.5
6
⇒
125
4
m/sec. Similarly, Time to cross railway crossing = (Lengths of train + railway crossing)/Speed of train ⇒ {
(125+75)
(
125
4
)
} ⇒
(200×4)
125
=
32
5
⇒ 6.4 seconds ∴ The time taken by train to cross the railway crossing is 6.4 sec.