Free Body Diagrams & Resultant Forces

• What are free body diagrams used for?

  To find the resultant force on an object
• What do free body diagrams represent?

  All the forces acting on a particular object
• How do we represent forces in free body diagrams?

  Using force arrows
• In the example of a plane, what forces are represented in its free body diagram?

  Thrust, drag, weight, and lift
• What does the direction of the force arrows indicate?

  The direction of the forces acting on the object
• How is the magnitude of a force represented in a free body diagram?

  By the length of the arrows
• What unit is used to label forces in free body diagrams?

  Newtons
• What happens to forces acting in different directions in a free body diagram?

  Some forces cancel each other out
• What is the resultant force?

  The overall force on an object
• How do you calculate the resultant force in vertical components?

  By subtracting opposing forces
• In the example, what is the vertical resultant force when there are 80,000 newtons up and 80,000 newtons down?

  Zero newtons
• What is the horizontal resultant force when there are 120,000 newtons to the right and 90,000 newtons to the left?

  30,000 newtons to the right
• What happens to the overall resultant force if air resistance is 120,000 newtons?

  The horizontal resultant force becomes zero
• What does it mean if both horizontal and vertical components are balanced?

  The object is in equilibrium
• What are the steps to find the resultant force using free body diagrams?

  1. Identify all forces acting on the object.
  2. Represent forces with arrows showing direction and magnitude.
  3. Separate forces into horizontal and vertical components.
  4. Calculate resultant forces for each direction.
  5. Combine horizontal and vertical results for overall resultant force.