Question #a16d3

2 Answers
Jan 22, 2017

Write each vector as x- and y-component vectors and add the component vectors.


Any vector can be broken down into a sum of two other vectors. Breaking the vectors you want to add into its horizontal and vertical components (x and y) is an easy convention to use to make the addition simpler. This guarantees that you will have components that are either in the same direction or perpendicular.

Let's say we want to add #vec A# and #vec B# as in the picture below:

Find the component vectors #color(red)(vec A_x)# , #color(red)(vec A_y)# , #color(blue)(vec B_x)# , and #color(blue)(vec B_y)#

Then, to add the vectors, you simply add the magnitudes of the x-components (or subtract if they are in opposite directions to each other) and the magnitudes of the y-components to find the components of the resultant vector.

You can then use the Pythagorean Theorem to find the magnitude of the resultant vector and trigonometry (#tan theta#) to find the direction.

enter image source here

Jan 22, 2017

see below


If you have them in component form and using the same basis, you just add the components. For example, assume that you are in 2-D Cartesian system, then for:

#mathbf v_1 = ((a),(b)), qquad mathbf v_2 = ((c),(d))#

...we say that:

#mathbf v_1 + mathbf v_2 = ((a+ c),(b+ d))#

You "just" add them. Is your thing more complicated?