What is the proper way to add vectors and what does the modulus notation mean?

[synkk]

Could anyone explain to me what all these notations are for the vectors? I've never used vectors before and all I know is that they show direction and magnitude, but don't know the actual notation. I'm assuming OA is the vector of O to A but what is it when they put the modulus around the vector?

Any links to vectors would be great, thanks.

 

[Doc Al]

I'm assuming OA is the vector of O to A but what is it when they put the modulus around the vector?

That indicates the magnitude of the vector.

Any links to vectors would be great, thanks.

Basic Vector Operations

 

[synkk]

That indicates the magnitude of the vector.

Basic Vector Operations

I see, for the magnitude you just use Pythagoras to find it? Could you not use the distance between two points?

 

[Doc Al]

I see, for the magnitude you just use Pythagoras to find it?

Yes.

Could you not use the distance between two points?

That amounts to the same thing.

 

[mtayab1994]

I see, for the magnitude you just use Pythagoras to find it? Could you not use the distance between two points?

The formula for finding the magnitude is :

$$|a|=\sqrt{a_{1}^{2}+a_{2}^{2}}$$

 

[e^(i Pi)+1=0]

hint: the absolute value of a complex number, just like any number, is its distance from zero...

 

[synkk]

The formula for finding the magnitude is :

$$|a|=\sqrt{a_{1}^{2}+a_{2}^{2}}$$

I'm not sure what A is.

Okay for this sketch:

Vector OB is 2(34)^1/2
Vector OA is 13

Now I'm reading about vectors online and it's saying that you can get to point A from OB, then to A. Now the distance from B to A is root 5, so OB to B-A should be the same as OA? Well If I add root 5 and 2(34)^1/2 it is not 13. Could anyone clear this up thanks.

 

[azizlwl]

Basic calculation
Use a graph paper and draw the vectors to scale.
From this drawing you can find the magnitude of vector AB

Later you will be able to use vector algebra to calculate the magnitude and direction.
http://emweb.unl.edu/math/mathweb/vectors/vectors.html

 

[Doc Al]

Now I'm reading about vectors online and it's saying that you can get to point A from OB, then to A. Now the distance from B to A is root 5, so OB to B-A should be the same as OA? Well If I add root 5 and 2(34)^1/2 it is not 13. Could anyone clear this up thanks.

It's true that the vector sum of $\vec{OB} + \vec{BA} = \vec{OA}$. But you don't add vectors by simply adding their magnitudes. To learn how to add vectors (there are several ways) explore the link I gave you earlier and this one: Vector Addition.