# Component vectors

1. Nov 26, 2009

### lovemake1

Hello, im slightly confused with component vectors.

if im trying to add two vectors, which are 33m/s [W33E] and 53m/s [N54W] i have to
break them down in to x and y component.
i can get them by using cos and sin.

but there are some occasions where im not sure if the degree im using is correct.

for example for 33m/s the xcomponent would be 33cos33 and ycompoent would be 33sin33.

when do we ever use 33cos-33 ? beacuse i know there are some occasions where negative angle is neccesary or even (180-33) obtuse angle to find the component.

please could anyone clarify this for me thanks,

2. Nov 26, 2009

### mikeph

I don't understand your notation [W33E]... are they something to do with the compass points?

3. Nov 26, 2009

### h4tt3n

To add two or more vectors, just add their x and y components respectively. Simple as that. Your notation seems odd, though.

4. Nov 26, 2009

### Staff: Mentor

Your [W33E] notation is incorrect. The other heading, [N54W], means 54 degrees west of north. The first one should probably be either N33E or S33E.

5. Nov 26, 2009

### LCKurtz

Draw the vector with its tail at the origin. Then draw a polar coordinate angle from the positive x axis to the vector. It doesn't matter whether you go counterclockwise with a positive $\theta$ or clockwise with a negative $\theta$. Do whichever seems more natural for the vector you are considering. In either case you will get $x = r\cos\theta,\ y = r\sin\theta$.