Force Vectors

1
Force Vectors

• Types of Forces
• Balanced and Unbalanced Forces
• Force Diagrams
• Adding Force Vectors

2
Types of Forces

• There are several common forces
• Fg is the force due to gravity (weight)
• Fn is a normal force
• Normal means that the force is applied
  perpendicular to the surface.
• Fa is force due to air friction (wind resistance)
• Ff is the force due to friction
• Always acts in the opposite direction of motion

3
Balanced and Unbalanced Forces

• Balanced Forces - The situation where forces in
  one direction exactly cancel the forces in the
  other direction
• The result is no acceleration, that is, the
  objects speed and direction remain unchanged
• Unbalanced Forces - The situation where forces in
  one direction do not cancel the forces in the
  other direction
• Results in acceleration, that is, the objects
  speed or direction changes

4
Comprehension Check

• When a book is sitting on a table, are the forces
  balanced or unbalanced?
• Balanced there is no change in speed or
  direction
• When baseball is flying through the air, are the
  forces balanced or unbalanced?
• Unbalanced the ball is slowing down and
  changing direction.

5
Force Diagrams

• Force diagrams are pictures that catalog all the
  relevant forces acting on an object

Jumping out of Plane
During Freefall
Immediately After Chute Opens
During Glide
Unbalanced Fg gt FA
Balanced FgFA
Unbalanced FA gt Fg
Balanced FgFA