Forces as Vectors

Naturally, vectors and vector algebra is important in physics.  The applet below is designed to illustrate a body, shown by the orange disk, being acted upon by three forces (denoted by blue arrows).  Since these forces are vectors, the net force (red arrow) is the vector sum of all three forces.

Applet by John Brecht

For more information about force tables, see Tom Henderson's Addition of Forces page.

Here is a very nice graphical depiction of a force table.  Notice that the gray ring centered  over the middle of the table by the three strings is represented by the orange disk in the above applet.  The three strings apply tension forces to the gray disk. If the gray disk is not accelerating (such as if it is motionless), then the three forces must sum to 0.