Free-Body Force Diagrams

Free-body diagrams are the simplest way to represent a situation in physics.  Here are a few guidelines to drawing them:

  • The object that we're talking about is drawn as a box.
  • All forces are drawn as arrows that start at the center of the object.
  • Length and direction of the arrow represent size and direction of the force.
  • All forces are labeled with their type, and sometimes with their magnitude.

Here are some common abbreviations that people use for the different forces:

  • Gravitational force, or weight, is written  
  • Normal force is written  
  • Tension is written  , or sometimes just T
  • Friction is written

Watch the following video to see some examples of free-body diagrams:

After you have completed this part of the lesson, you can check the associated box on the main course page to mark it as complete

Last modified: Tuesday, 1 September 2015, 3:14 PM