Download Free Body Diagrams

Free Body Diagrams
A Free Body Diagram (FBD) is a visual
representation of all the forces acting
on a single object
FBDs are extremely powerful problem
solving tools that bridge the gap between
qualitative analysis and a quantitative
mathematical representation
Drawing an FBD…
• A simple dot can be used to represent the object
in question
• Identify the forces acting ON that object only
• Draw one arrow to represent each force acting
ON the object
– All arrows should be drawn from the dot or the center
of the object
– The arrows point in the direction of the force.
– The length of the arrow represents the relative
magnitude of the force…ie longer arrows = larger
force
Example 1
A lab cart resting on a worktop
Normal Force
Weight/Force due to Gravity
Example 2
A lab cart moving with a constant velocity across a surface
Normal Force
Applied Force
friction
Weight
Example 3
A lab cart accelerating across a surface
Normal Force
Applied Force
friction
Weight
Example 3
A tetherball while swinging at a constant speed around a pole
Tension
Weight