Two trains leave the station at the same time, one heading west and the other east. The westbound train travels at 100 miles per hour. The eastbound train travels at 90 miles per hour. How long will it take for the two trains to be 342 miles apart?

Do not do any rounding.

Question

Two trains leave the station at the same time, one heading west and the other east. The westbound train travels at 100 miles per hour. The eastbound train travels at 90 miles per hour. How long will it take for the two trains to be 342 miles apart?

Do not do any rounding.

***[isuru]*** · Answer

u can use the relative velocity here

***[isuru]*** · Answer

one train travels at 100 miles per hour... the other travels in opposite direction at 90 miles per hour...
 so at the end of one our one train will be at a point 100 miles away from the starting point while the other will be at a point 90 miles away from the starting point in the opposite direction

so the distance between 2 trains will be 190 moles at the end of one hour... and at the end of 2 hours it will be (2x 190) = 380... and so on...

so the distance between 2 trains increase at a rate of 190 miles per hour..
so the time to become that value 342 is 342/190 = 1.8 hours...

got it :) ?

anonymous · Answer

Ooh, So basically if I write down a line and make it to where 1 hour is 100 on one side and 90 on the other that turns out to be 190 and since 380 is bigger than what we are looking for we divide it by 190? o:

***[isuru]*** · Answer

yes

anonymous · Answer

Okay, Okay. I got it. Thank you! (: