1. Force Free-body Diagrams 1 Steps to Solving the Problem Drawings Calculations

2. Force Free-body Diagrams 2 Using a free-body diagram… 1.Draw a picture of the problem. 2.Draw the object on which the force is being sought. 3.Draw and label the forces and the acceleration. 4.Choose and draw your axes. 5.Determine the magnitude of the known forces and the acceleration if it is known. 6.Determine the angle of all of the forces and the acceleration (from the x-axis going counterclockwise). 7.Determine the components of each force and the acceleration. 8.Add the components of all of the forces. 9.Use Newton’s second law to solve the problem.

3. Force Free-body Diagrams 3 An example… Bailey-the-Wonder-Dog is walking down a 20 o slope with a constant acceleration of 1m/s 2. Bailey herself has a mass of 35 kg. What is the coefficient of friction acting between each of Bailey’s legs and the slope?

4. Force Free-body Diagrams 4 θ

5. Force Free-body Diagrams 5 θ

6. Force Free-body Diagrams 6 y x θ y x

7. Force Free-body Diagrams 7 y x θ θ

8. Force Free-body Diagrams 8 y x Weight

9. Force Free-body Diagrams 9 y x Normal Force

10. Force Free-body Diagrams 10 y x Friction

11. Force Free-body Diagrams 11 y x Acceleration

12. Force Free-body Diagrams 12

13. Force Free-body Diagrams 13

14. Force Free-body Diagrams 14

15. Force Free-body Diagrams 15