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 a free body diagram of a plane, what does the forward arrow represent?

  The thrust of the plane
• What does the downward arrow in a free body diagram indicate?

  The weight of the object
• Why do we label forces in newtons?

  To indicate the magnitude of the forces
• What happens to forces acting in opposite directions in a free body diagram?

  Some forces cancel each other out
• How do you calculate the resultant force in vertical components?

  By subtracting opposing forces
• If a vertical force of 80,000 newtons acts up and 80,000 newtons acts down, what is the resultant force?

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

  30,000 newtons to the right
• What does it mean if both horizontal and vertical components are balanced?

  The object is in equilibrium
• What would happen if air resistance was 120,000 newtons?

  The horizontal resultant force would be zero
• What indicates that there is no resultant force acting on an object?

  Both components are perfectly balanced
• What are the steps to find the resultant force using free body diagrams?

  1. Identify all forces acting on the object.
  2. Draw arrows to represent each force.
  3. Label the forces in newtons.
  4. Calculate vertical and horizontal components separately.
  5. Subtract opposing forces to find resultant force.