2. Copyright © 2004 S. B. Egliwww.stuegli.com Created by Mr. Egli September 2004 mr.egli@phyzx.com

3. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Axis – straight line at center of and normal to rotation path

4. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Radius - perpendicular distance from axis to center of object

5. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion - Ball on String When the string breaks which way does the ball go? Click on your choice below. String A B C ABC We know from Newton that bodies move in straight lines unless acted on by external forces! This direction is the TANGENT to the circle (path of motion)

6. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Centripetal Force = mv 2 /r ‘the force that is acting towards the axis’ NOTE: this can be a ‘push’ or a ‘pull’ v r

7. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion AxisRadius Linear Speed

8. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Revolution – axis outside of the object (moon orbiting the earth is revolving) Rotate – axis inside the body (earth rotates on its axis)

9. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Linear speed

10. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com

11. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com The Radius Vector The radius for circular motion is a vector. It is shown at the left drawn in red. This radius vector locates the orbiting object. One should imagine an x, y coordinate system with its origin at the center of the circle. The radius extends from this origin to the position of the object. PreviousNextIntroduction Home The radius vector.

12. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Rotational Speed Units

13. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Centripetal Force = mv 2 /r ‘at ½ the radius the acceleration is doubled’ v r

14. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Centripetal Force

15. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Centrifugal force

16. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Simulated Gravity

17. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion Sample Solutions

18. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion

19. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.com Circular Motion

20. Copyright © 2004 S. B. Egli Copy slide to word Copy slide to word Copy Screen to Word Copy Screen to Word google Excel www.stuegli.comPhysics