A free body diagram is a visual representation of the forces acting on a system or object. It consists of a simple sketch of the object with arrows representing the magnitude and direction of all the forces acting on it.
Including force in a free body diagram helps to accurately analyze the motion of a system or object. By considering all the forces acting on the object, we can determine the net force and therefore predict the resulting motion.
All types of forces acting on the object should be included in a free body diagram, including gravitational, frictional, normal, tension, and applied forces. It is important to consider all forces, even those that may seem negligible, in order to accurately analyze the system.
The direction of the forces in a free body diagram should be based on the direction that the force is acting on the object. For example, a force pushing an object to the right should be represented by an arrow pointing to the right.
While free body diagrams are a useful tool for analyzing the forces acting on a system, they do have limitations. They only consider forces in a single plane and do not take into account the effects of rotation or acceleration.