1. Physics Cir cu lar Mo tion

5. No external force The body remains at rest. The body moves with a constant speed . Newton’s first Law

7. For fixed force A body with a larger mass moves with a smaller acceleration . A body with a smaller mass moves with a larger acceleration . Newton’s second Law

8. For fixed mass A body with a smaller net force moves with a smaller acceleration . A body with a larger net force moves with a larger acceleration . Newton’s second Law

10. Body A exerts a force on body B, then body B exerts an equal and opposite force on body A. Newton’s third Law Body A Body B Force on B by A Force on A by B

11. Newton’s third Law

12. Circular Motion in horizontal circles

13. Circular Motion in horizontal circles Angular velocity  =  / t Linear velocity v =  r Centripetal force F = m r  2 = m v 2 / r Centripetal acceleration a = r  2 = v 2 / r

14. Circular Motion in horizontal circles Conical pendulum

15. Circular Motion in horizontal circles Conical pendulum Do you remember what kind of forces provides the centripetal force to the bob ? Tension T Weight mg Centripetal force

16. Vertical circular motion Bucket and water Does the water spill out the bucket when whirling ? If no, why doesn’t it spill out ?

17. Vertical circular motion Bucket and water What kind of motion does the bucket perform ? Vertical circular motion What kind of force provides the centripetal force F c to the bucket ? Tension T Weight mg

18. Vertical circular motion Bucket and water What kind of force provides the centripetal force F c to the bucket at the highest position ? F c = T + mg Tension T Weight mg

19. Vertical circular motion Bucket and water What kind of force provides the centripetal force F c to the bucket at the lowest position ? F c = T - mg Tension T Weight mg

20. Vertical circular motion Bucket and water What kind of force provides the centripetal force F c to the water at the highest position ? F c = R + W Reaction of the bucket R Weight of water W

21. Vertical circular motion Bucket and water What kind of force provides the centripetal force F c to the bucket at the lowest position ? F c = R - W Reaction of the bucket R Weight of water W

22. Vertical circular motion Loop-the-loop

23. Vertical circular motion Loop-the-loop What kind of force provides the centripetal force F c to the mass ? The reaction of the track

24. Class exercises M.C. Exercise Main menu True or False

29. You are wrong. Try again ! Sorry ！ return

30. Congratulation ! Correct ! Return