First 321 words of the document:
If you've ever watched the comedy film "Airplane" there's a memorable cockpit
scene where the Captain is called Roger and the Navigator Victor. It goes
something like this:
Captain: "Give me a Vector Victor"
Navigator: "Roger, Roger" and so it goes on...
So, what is a Vector? It's a thing which has both size and direction. So what's
that mean? Well, think of the speed of a car being 70 miles per hour. Speed is
not a vector as it only has size (10mph is a small size and 70mph a much bigger
size), things with only size are called Scalars.
Now, think of a car doing 70mph in an North Easterly direction (i.e. a bearing of
45o from North). We are now thinking of a speed and direction, this is called
velocity and is an example of a vector.
We can show what this velocity looks like with an arrow:
This sort of diagram can be used as a model to show an
image of a vector. The length of the vector arrow is used
to represent its size (in our case 70mph). The direction of
the arrow is measured as we would any other direction
(by the angle, which is 45o in our case).
Just to make things doubly painful when dealing with vectors, there are various
ways of indicating that something is a vector. Here are 3 ways of representing
the same thing in books:
The last way shown to indicate a vector (by using bold type) is obviously tricky to
do if you are writing by hand. Here the convention is normally to use a squiggly
line underneath the letter to indicate that you are talking about a vector e.g.
Other pages in this set
Here's a taster:
Now you know how vectors are written, we can see how vectors are added and
If you are at Heathrow and want to fly to Edinburgh, you can either go straight
there or you can make two flights by stopping off halfway at Manchester. Each
flight can be shown as vectors:
Here the flight from Heathrow to Manchester is shown
as vector a and the flight from Manchester to
Edinburgh is shown as vector b.…read more