Monday, December 7, 2009

Math Fact of the Day

A fellow teacher told me this today and it struck me as being interesting. Therefore, I wanted to share it.

Suppose you leave your house and walk a path to some other destination at 8 A.M. on Monday. You can walk at any speed you want, you can even stop your walk and stand still for a while, and you can even backtrack your path and then walk forward again. But, at some point on Monday, you reach your destination and sleep over.

Then, on Tuesday morning, you leave your destination at 8 A.M. and return home again. You walk with your speed being totally random and independent of your speed from Monday. Infact, for the sake of argument, you do something totally different (like, you sprint all the way home on Tuesday when on Monday you crawled, stood still, went back and forth, etc...)

So, here's the fact: There will be a location between your home and the destination that you passed both going to the destination and returning home at the exact same instant on both days.


Weird...

3 comments:

popsrick said...

How?

Evan said...

I think you have to look at this problem as two dots (representing you) moving across a line (the route) from point A to point B. If you draw the problem, you move two dots across the same line (as the route is the same), one dot going from point A to point B and the other from Point B to Point A. So if you draw both events occurring simultaneously (because you left each point at the time) you draw two dots, starting at opposite ends of same the line, at some point, those dots intersect. At the point of intersection is when you will be at the exact place at the exact time.

Right? Max, did I explain this correctly?

Anonymous said...

You mean, "Walt, did I explain this correctly?" :)

But yes, absolutely.