A free body diagram (FBD) is a visual representation that depicts the forces acting on an object in a simplified manner, isolating the object of interest from its surroundings.
In a free body diagram, arrows are used to represent the forces acting on the object. These arrows convey information about the magnitude and direction of the forces.
The direction of the arrow indicates the direction in which the force is acting on the object. For example, if a force is pulling an object to the right, the arrow representing that force will point to the right.
The length of the arrow is proportional to the magnitude (strength) of the force. A longer arrow represents a stronger force, while a shorter arrow represents a weaker force.