Simply put, in a free body diagram, all the forces acting on the given object are represented as arrows. Let me start with a simple case, a box sitting on a table.

A free body diagram models the forces acting on an object. The object or 'body' is usually shown as a box or a dot. The forces are shown as thin arrows pointing away from the centre of the box or dot.

In this Closer Look segment on free body diagrams, we break down how to draw free body diagrams and work through three different examples.

Free body diagrams Show the forces acting on an object in a free body diagram. The arrows represent the size and direction of the forces acting. When drawing a force diagram: ...

Step 1: FBDs Draw a free body diagram (FBD) of the disk. You will need to temporarily define a coordinate representing the rotation of the disk. For example, you could use the angle θ as the angle of ...