the train 400 m long is running at a speed of 40 km per hour how long it will it take to cross a bridge 800m long
Answers
Answer:
108 Seconds
Step-by-step explanation:
If the tip of a train starts at the tip of the bridge, we know that to get the train to the other end, it would require us to fully get the tail of the train off the bridge. 400 m gets our tip halfway, 800 m gets our tip the full way, and then 1200 m would get the tail all the way out, so we know that it is 1200 m we are going.
If the train is travelling 40 km per hour, that means that it is the same as travelling 40000 m per hour.
40000 m per hour, would be the same as 40000 m per 3600 seconds.
Lets simplify the fraction, and by doing this, we find out that the train travels 100 m per 9 seconds. We need to know how long it would take for 1200 m.
Cross multiply!!!
40000 m / 3600 s = 100 m / 9 s = 1200 m / ? s
Let's use the last two to find the answer
(100 m x ? s) = (1200 m x 9 s)
(100 m x ? s) = (10800 m x s)
(100 m x ? s) / (100 m) = (10800 m x s) / (100 m)
? s = 108 s
Therefore it takes the train 108 seconds to to pass the bridge
Hey there!!! Let me know if this was a good explanation, and if there is anything I can improve on.