A pictorial device which analyzes forces present on any body with the use of vectors. Allows easier grasping of problems involving either objects at equilibrium or in motion. Can be used to predict presence of forces.
A free body diagram is a diagram that is modified as the problem is solved. Typically, a free body diagram consists of the following components:
- A simplified version of the body (most commonly a box/ball)
- A coordinate system
- Forces are represented as arrows pointing in the direction they act on the body
- Moments showed as curved arrows pointing in the direction they act on the body
- The number of forces acting on a body depends on the specific problem and the assumptions made.
Exclusions in a Free Body Diagram
- Bodies other than the free body diagram
- Constraints
- Internal forces
- Velocity and acceleration vectors
