The first step is to identify the object or system you want to analyze. This could be a single object or a group of connected objects. Once you have identified the object, you can draw a free body diagram to represent all the external forces acting on it.
Yes, it is important to include all the external forces acting on the object in order to accurately analyze its motion. This includes forces such as gravity, normal force, friction, and any applied forces.
You can determine the direction and magnitude of the forces by considering the physical situation and using known principles, such as Newton's laws of motion. If necessary, you can also use measurements or calculations to determine the values of the forces.
Your free body diagram should include a simple, labeled sketch of the object and all the external forces acting on it. The forces should be represented by arrows pointing in the correct direction and labeled with their corresponding values.
Some common mistakes to avoid include forgetting to include all the forces, drawing the forces with incorrect directions, and not labeling the forces with their corresponding values. It is also important to make sure your diagram is neat and organized so that it is easy to interpret and analyze.