We know that when two vectors are in the same dimension, they can
be added arithmetically. Suppose we have two vectors that are on a
north-south, east-west grid – as shown below. One of the methods we can
use to add these vectors is to resolve each one into a pair of vectors
that lay on the north-south and east-west axes.
The two vectors we are to add is a force of 65 N at 30° north of east and a force of 35 N at 60° north of west.
We can resolve each of the vectors into two components. The
components are on the axes lines. Each vector is resolved into a
component on the north-south axis and a component on the east-west axis.
Using trigonometry, we can resolve (break down) each of these
vectors into a pair of vectors that lay on the axial lines (shown in red
above).
The east-west component of the first vector is (65 N)(cos 30° ) = (65 N)(0.866) = 56.3 N east
The north-south component of the first vector is (65 N)(sin 30°) = (65 N)(0.500) = 32.5 N north
The east-west component of the 2nd vector is (35 N)(cos 60°) = (35 N)(0.500) = 17.5 N west
The north-south component of the 2nd vector is (35 N)(sin 60°) = (35 N)(0.866) = 30.3 N north
Summary
- Vectors can be resolved into component vectors that lie on the axes lines.
Practice
A video showing the trigonometry of resolving vectors into axial components and also shows a number of solved example.
Review
- A force of 150. N is exerted 22° north of east. Find the northward and eastward components of this force.
- An automobile travels a displacement of 75 km 45° north of east. How far east does it travel and how far north does it travel?
