Question

4. A train 270 metres long is running at a speed of 36 km/h. How long will it take to cross a bridge
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Answer 1

$\bigstar$ Correct Question :

            A train 270 metres long is running at a speed of 36 km per hour,How long will it take to cross a bridge of length 180 m

$\bigstar$ Answer :

Length of the train = 270 m

Speed of the train = 36 km/h

Length of the bridge = 180 m

Total Distance = Length of train + Length of bridge

⇒ Total Distance = 270 m + 180 m

⇒ Total Distance = 450 m

Now speed of the train is in km/h . So we need to convert it into m/s.

For that we need to multiply with 5/18.

⇒ Speed = 36 * ( 5/18 )

⇒ Speed = 10 m/s

We know that ,

$\bf Speed =\dfrac{Distance}{Time}\\\\\implies \bf Time=\dfrac{Distance}{Speed}\\\\\implies \bf Time = \dfrac{450}{10}\\\\\implies \bf Time = 45\ seconds$

So , it will takes 45 seconds to cross bridge

Answer 2

GIVEN:

LENGTH OF TRAIN=270m

LENGTH OF BRIDGE=180m

SPEED OF TRAIN=36kmph

36kmph=36 x 5/18ms=10m/s

FORMULA:

$time = \frac{distance}{speed}$

ANSWER:

DISTANCE=180+270=4450m

SPEED=10m/s

TIME = 450/10=45 SECONDS

NOTE: LENGTH OF THE

BRIDGE(180m) IS NOT

GIVEN IN UR QUESTION.