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
• What does the length of the arrows in a free body diagram indicate?

  The magnitude of the force
• What are the four forces acting on a plane in the example given?

  Thrust, drag, weight, lift
• Why do we need to consider both magnitude and direction for forces?

  Because forces are vectors
• How do we calculate the resultant force from multiple forces?

  By considering horizontal and vertical components separately
• In the vertical component example, what is the resultant force when there are 80,000 newtons up and 80,000 newtons down?

  Zero newtons overall
• What is the resultant force in the horizontal component with 120,000 newtons right and 90,000 newtons left?

  30,000 newtons to the right
• What happens to the resultant force if air resistance equals 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 is the overall resultant force when the object is in equilibrium?

  No resultant force acting on it
• What are the steps to analyze a free body diagram?

  1. Identify all forces acting on the object
  2. Represent each force with arrows
  3. Determine the magnitude and direction of each force
  4. Calculate the resultant force by considering components