Question

On a free-body diagram, you sketch

A. all of the forces exerted on all of the objects in the diagram.
B. [It depends on the specific problem.]
C. all of the forces exerted on one object in the diagram.
D. all of the forces that one object exerts on all of the other objects in the diagram.

Answer 1

Free-body diagrams are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation.

A free-body diagram (or FBD) displays an object taken in isolation with all the forces that act on that object.

Therefore the forces exerted by the object itself are not included.

There is no hard and fast rule about the number of forces that must be drawn in a free-body diagram. The only rule for drawing free-body diagrams is to depict all the forces that exist for that object in the given situation.