1. ICNS 132 : Circular Motion Rotational Motion Weerachai Siripunvaraporn Department of Physics, Faculty of Science Mahidol University email&msn : wsiripun2004@hotmail.com

3. even though an object moves at a constant speed in a circular path, it still has an acceleration.

8. Rotational Motion & Circular Motion & SHM Rotational Motion (Rigid Object) SHM Motion

10. Polar Coordinate P is rotated counter-clockwise.

12. We choose a reference line on the object, such as a line connecting O and a chosen particle on the object. The angular position of the rigid object is the angle  between this reference line on the object and the fixed reference line in space, which is often chosen as the x axis. This is similar to the way we identify the position of an object in translational motion—the distance x between the object and the reference position, which is the origin, x = 0. final angular position  f Initial angular position  i

13. The angular velocity of an object describes how fast it is turning about an axis in the time interval  t, and is defined as follows:

19. Angular velocity (ω) Tangential velocity (v)

20. although every point on the rigid object has the same angular speed, not every point has the same tangential speed because r is not the same for all points on the object.

21. tangential acceleration of the point P

22. centripetal acceleration at that point