So what's a vector?

A vector is a representation we use to help us solve a problem.  A vector is some quantity with a direction. 

EXAMPLE:  55mi/Hr is a speed.  Since there is no direction given, this quantity is called a scalar.  For some problems, this is sufficient to get the work done.
55mi/Hr West is a vector.   Now we know which way the car is going.  Why would we care about the direction?

Here's a question that will make the purpose clearer...

Two identical cars collide and stick together.  Each is going 10m/s.  Where will they end up compared to the crash site?

Now you see the big deal...

  • If the cars hit head on, the tangled mess will remain at the crash site.
  • If one was going North and one West, they will end up somewhere Northwest.

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    So we do need to know about vectors.  We must learn about angles and trigonometric functions.  Eventually we will learn about momentum and forces and many other fields where vectors are commonly used.