1. Forces and Force Diagrams
SMS

2. Unbalanced forces: Change the motion of an object!
Force: Push or pull!
Unbalanced forces: Change the motion of an object!
Maybe stopping an object from moving or putting an object in motion

3. Balanced Force: Forces are equal and opposite to each other!
Also called F surface
F Normal
F Gravity

4. Balanced Forces:
Balanced forces have a net force of zero!!

5. Types of Forces: Gravity: always pulling down!
** Every force diagram should include this!
Surface/Normal: the force that is pushing up from the ground/table/floor
** should also be in every force diagram!

6. Types of Forces: Friction: Goes in the opposite direction of motion!
Friction slows things down!
Will only be found in force diagrams for moving objects
Push

7. Push or Pull F Normal F Motor F Friction F Gravity
These will be named different things depending on what object you are looking at.
Example: a car could be F motor or F push
F Normal
F Motor
F Friction
F Gravity

8. Net Force Net Force: overall direction of combined forces
F push = 20 N

9. Net Force
Find the difference to see which direction an object will move

10. Drawing a Force Diagram
Every diagram should include:
F gravity
F normal/ F surface
Diagrams for moving objects:
F friction
F for whatever is making the object mover
Examples: F propeller, F pull, F push, F motor

11. Drawing a Force Diagram…
Arrows for balanced forces should be about equal
When forced are unbalanced, on arrow should be larger
F normal : 9 N
F friction : 5 N
Net Force: 15 N
Book
F push : 20 N
F gravity : 9 N

12. Practice 1: Draw a force diagram for a book on a table
Include: F gravity and F normal

13. Practice 2: Complete the force diagram below:
A shopping cart is moving to the right with a force of 40 Newtons. Friction is opposing this movement with a force of 5 Newtons. Include gravity, the normal force, and the net force

14. Practice 3:
Draw a force diagram of a car moving to the right with a force of 20 N. Friction is opposing this with a force of 5 N. Include gravity and the normal force. What is the net force for this problem?