1. Test Review
Dynamics

2. Newton’s Laws
Newton’s First Law: An object at rest will remain at rest and an object in motion will remain in motion until an outside force acts on it.
This is often called the Law of Inertia.

3. Inertia
Def: The desire of an object to resist being moved…Or, if it’s moving to resist being stopped.

4. Examples
Look at the examples of inertia with your teacher.

5. Mass-Inertia Relationship
More Mass = More Inertia

6. Example
Complete the example question about inertia in car crashes on your review sheet.

7. Newton’s Second Law
The 2nd Law is basically just an equation:
F=ma

8. Examples
Complete the two example problems on your review sheet about Newton’s Second Law.

9. Weight
Def: The force of gravity on an object’s mass. Found using F=ma.
On Earth, a = -9.8m/s2 to determine the weight of an object.

10. Examples
Complete the three example problems about weight on your review sheet.

11. Elevator Problem
Work this problem with your teacher. Think about the forces acting on the scale while the elevator is sitting still, or accelerating.

12. Accelerating Block Problems
Try to complete the three problems involving accelerating systems.
Try to correctly apply F=ma to each situation.

13. Newton’s Third Law
Complete the Free Body Diagrams and answer the questions with your teacher.

14. Equilibrium Def: A condition in which the net force on an object is 0.
This occurs when ALL forces cancel out, or there are none at all.

15. Friction
Def: A force that opposes the motion of an object. Friction is caused by two surfaces in contact with each other.
Static Friction: Friction that keeps objects still.
Kinetic Friction: Friction that occurs when an object is sliding.

16. Static > Kinetic Friction
Static Friction is always greater than Kinetic Friction.
Static > Kinetic

17. Friction Contributing Factors -Roughness of Surfaces
- Weight of objects
- Normal Force

18. Force (Friction) = coefficient of friction * Normal Force
Formula:
Ff=µFn
Force (Friction) = coefficient of friction * Normal Force

19. Examples
Do the example problems on your review sheet.

20. Friction- Graph Static Friction- Object remains still
Object breaks free and starts moving.
Kinetic Friction- Object moves at constant velocity.
Force (N)
Time (s)

21. Newton’s Law of Gravitation
Allows you to determine the force of gravity between ANY two objects separated by ANY distance.

22. Inverse Square Law Once you know Fg at one spot,
If you double the distance, divide Fg by 4.
triple
quadruple d
Fg=1000N

23. Example.
Complete the last example on your review sheet.

24. “Cheat Sheets” 1 page, front and back. Hand written.
Anything on it you want.