Final answer:
In a free-body diagram, the object is represented as a single point, where forces acting on the object are shown as arrows extending from this point.
Step-by-step explanation:
When constructing a free-body diagram, the object in question is represented as a single point regardless of its actual shape or size. This diagram is a graphical illustration showing all the forces acting on the object. The forces are depicted as arrows extending from the single point, with each arrow representing a different force, such as gravity, friction, tension, etc. The length of the arrow signifies the magnitude of the force, while the direction of the arrow shows the direction in which the force is acting.