Question

A train 100 m long is running speed of 54 km/hr . It crosses bridge in 12 sec find length of bridge

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

The speed of a 100m lon train is 54 km/h, It crosses a bridge in 12 sec, the length of the bridge  is $80m$

​Step-by-step explanation:

• The speed (V) of a body is the distance(d) covered by it divided by the time taken (t) to cover the distance

        $V=d/t$

From the quest

length of the train $l=100m$

assume that the length of the bridge is x

time taken to cross the bridge  $t=12s$

speed of the train $V=54km/h=54*5/18=15m/s$

but speed is the total distance divided by time

total distance =length of the train +length of the bridge

⇒

$V=x+l/t$

$15=\frac{x+100}{12}$

$180=x+100\\x=180-100=80m$

so the length of the bridge $x=80m$