Question

if a train goes at 120 km/h and it takes 9 seconds to cross a post then the length of the train is ...

Answer 1

speed = 120km/hr

speed = 120 × 1000m /3600 sec

speed = (100/3)m/s

time = 9 seconds.

so distance = speed × time

= 100/3 m/s × 9 s

= 100 m × 3

= 300 m

so the distance travelled in the time taken to cross the post is the length of the train.

so length of the train is 300m.

hope it helps u

Answer 2

Solution :

Speed of the train(s)=120km/h

= 120 × ( 1000m/60×60s )

= ( 120 × 10 )/( 6 × 6 )

= (100/3 )m/s

Time ( t ) = 9 sec

Now ,

Length of the train

= distance travelled

= s × t

= ( 100/3 ) × 9

= 100 × 3

= 300 m

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