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Free Body Diagrams. Pictures and Notes. There must be a simple way to show all the forces on an object visually. . Free-body diagrams. Free Body diagram. Object represented by dot Forces represented by arrows Each arrow points away from dot Each arrow is labeled (F g , F a , F f …).
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Free Body Diagrams Pictures and Notes
There must be a simple way to show all the forces on an object visually. Free-body diagrams
Free Body diagram Object represented by dot Forces represented by arrows Each arrow points away from dot Each arrow is labeled (Fg, Fa, Ff…)
Labeling Forces By letter and subscript(s) The letter will usually be F (for Force) but can be other values The subscript is meant to define the specific type of force or its origin, such as Fg (force of gravity) Ff (force of friction FBob (force applied by Bob)
Which forces are shown on the diagram? Only represent the forces that are applied to the object, NOT forces the object applies to other things or the surrounding environment
Direction of Motion arrow Generally all arrows represent forces applied to an object. If object is moving, it is good to draw an additional arrow separate from the diagram which indicates the direction of motion This info is used to determine the direction of certain force values like friction, air resistance
Fground Fgravity or Fweight
What would be the free body diagram of ….. What are the forces on the dog?
Answer Direction of motion arrow (DoM) Reactive force of ground Applied force of ground pushing paws forward Force of leash Friction force Weight of dog