Stuff and Stuff Responds
A reader from somewhere writes:
Oooooo a question for your project!
‹thinks›
If you were stranded on a desert island and could stock your reed hut with only eight items (excepting food and survival items), what would they be? No electricity, remember!
Sincerely,
Jill
Stuff and Stuff muses:
Well Jimmy, to answer this question, we must first, set up your variables:
We’ll call the velocity of trains A & B, Ra and Rb, respectively. So: Ra=100mph and Rb=60mph
And the distance that train A (Da) travels is the total distance (L) minus the distance of train B (x). So: Da=L-x
We also know that the distance between LA and Chicago is 2018 miles
Now, at the point where the trains cross, their times are equal, meaning that we can take the basic formula: D(istance)=R(ate)*T(ime) and set the times of the two trains equal to each other. In other words:
T=Da/Ra=Db/Rb Using our variables, this becomes: L-x/100=x/60, and solving for x yields 756.75 miles
But this doesn’t entirely answer your question. You wanted to know when the trains cross. Well, using our formula, D=RT, again: 756.75miles=60mph*T, and solving for T yields 12.6125 hours
Knowing that train B left LA at 12:00 PM, we add 12.6125 hours, which means that Train A from Chicago crosses paths with Train B from LA at approximately 12:37 A.M., which puts you somewhere in Colorado!
Thanks Billy…and to everyone else, keep sending in your questions!