Homework Help

Two trains 100m and 90m are running on parallel lines in the same direction with speeds...

user profile pic

falsefantasy | TA , Grade 9 | (Level 1) Salutatorian

Posted January 2, 2013 at 10:13 AM via web

dislike 1 like

Two trains 100m and 90m are running on parallel lines in the same direction with speeds 35km/h and 50km/h respectively. In what time will they pass each other?

Please give the solution with all the steps.

1 Answer | Add Yours

user profile pic

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted January 2, 2013 at 3:26 PM (Answer #1)

dislike 1 like

The trains are 100m and 90m long and are running on parallel lines in the same direction. The speed of the trains is 35 km/h and 50 km/h respectively.

The faster train will cross the slower one and to do so it has to travel a distance equal to the sum of the length of the two trains. This is equal to 100 + 90 = 190 m. The difference in the speed of the two trains is 50 - 35 = 15 km/h, this is the speed with which the faster train moves ahead of the slower one.

To travel a distance of 190 m at 15 km/h requires a time equal to 0.190/15 = 19/1500 hr or 0.76 minutes

The trains cross each other in 0.76 minutes.

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes