There are two modes in this simulation, since vector addition can be pictured using a tail to tail view or a tip to tail view. You can toggle between the two views at any time using the radio buttons.

You can adjust the direction and magnitude of the blue and yellow vectors by using your mouse to drag their tips. What is the sum of the two vectors? Use the components of each vector, shown along the coordinate axes, to determine the appearance of the sum. Sketch a prediction, then click the “show sum” button to see the computer calculate the sum.

How are the components of the red sum vector determined from the components of the blue and yellow vectors? Use the tip to tail mode to see the answer.

Drag the tip of the yellow vector; does the red vector always move when you move the yellow vector?

Find one configuration where the sum of the magnitudes of the yellow and blue vectors equals the magnitude of the red vector. What is special about this arrangement of the vectors?