Question

the length of a bridge which a train 130 metres long and travelling at 45 kilometre per hour can cross in 30 second is​

Answer 1

Solution:-

Given:-

Time = 30 seconds .

Speed of Train = 45 km/hr.

Changing km/hr into m/s.

=) 45 × 5/18

=) 12.5 m/s

=) Speed of Train = 12.5 m/s.

Now,

Distance Covered = Speed × Time

=) Distance Covered = 12.5 × 30

=) Distance Covered = 125 ×3

=) Distance Covered = 375 m.

Now,

Length of the Bridge = Total Distance Covered by the Train - Length of the Train

=) Length of the Bridge = 375 - 130

=) Length of the Train = 245 m.

Answer 2

Answer:

245 m

Step-by-step explanation:

Let, Length of Bridge = x

Total Distance = ( x + 130 )m

Speed = 45 km/h

          = 45 * (5/18) m/s

          = 25/2 m/s

Time = 30 s

So,

Distance/Time = Speed

or, ( x + 130)/30 = 25/2

or, x = 245

.................Thanks..................