it takes 400 seconds for a train to completely cross two points A and B which are at a distance of 7.8km. what is the speed of the trains, if the length of the train is 200m
Answers
Answered by
6
Answer:
The speed of the train is 40 km/h.
The distance to be covered by the train is its length+ length of the bridge and its length once again to clear off the bridge. So the engine has to cover 400+800+400 = 1600 m from the time it touches the bridge and till the guard van leaves the bridge.
The train covers 40*1000m or 40000m in 60 minutes.
So to cover 1600 m it takes 1600*60/40000 = 2.4 minutes.
Answered by
67
Step-by-step explanation:
Given that,
length=200m
=200/1000 =0.2km
distance=7.8+0.2=8km
time=400sec
=400/3600 =1/9hours
speed =distance/time
=8/(1/9)
=8*9
=72km/hr
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