How Do You Calculate Displacement Using Vector Components?

[oldspice1212]

A disoriented physics professor drives a distance 3.40km north, then a distance 3.80km west, and then a distance 1.55km south.

Find the magnitude of the resultant displacement, using the method of components.

Find the direction of the resultant displacement, using the method of components.

I tried drawing it got some weird shape...not a triangle

 

[genericusrnme]

"using the method of components"
Drawing triangles isn't the method of components!

What would the displacement vector look like at each step?

 

[majormaaz]

Just think for a moment; you go north a certain distance, and you also go south a certain distance (not in that order). They are opposite directions, right?
Just try to think of the problem as having ONE vertical vector and ONE horizontal vector.
If you have more than one vector in either dimension, add them up to get one vector.

Then you get your triangle.

 

[oldspice1212]

Shouldn't I subtract the south distance from the north?