What are free body diagrams and what are they used for?

In a free-body diagram you see an object and all the forces acting on that object.

• What are free-body diagrams?A free-body diagram displays an object taken in isolation with all the forces that act on that object.

• What are they used for?They help us eliminate all the distractions (external elements) and focus ourselves on the objects alone. Free-body diagrams make the examination of objects and all the forces acting on those objects easier.

You can read the whole article and see examples here: What a free-body diagram is and how to draw it