How many seconds does it take one train 150 m in length with 10 m/s and another train 250 m in length with 15m/s to pass each other?
Answer
Since both of end approaches 25 m in every second, the time of meeting of ends is 400/25= 16 seconds.
16 seconds
Solution
The time concerning two trains passing is time after the head of two trains meets until the end meets.
At the time of the head of a train meeting, the distance of end of each train is 150m + 250m = 400m.
At the time of the head of a train meeting, the distance of end of each train is 150m + 250m = 400m.
Since both of end approaches 25 m in every second, the time of meeting of ends is 400/25= 16 seconds.