Motion is defined relative to a frame of reference. The frame of reference is the object used to determine if something is moving. The most common frame of reference is the Earth. Position refers to an object's location. Motion occurs when an object's position changes relative to the chosen frame of reference.

1. Notes: Motion CW: Velocity is Relative H: Frames of Reference

2. Motion February 6, 2009

3. Objectives Define the frame of reference and identify the moving object in different situations Name the most commonly used frame of reference Define position and motion

4. Background The early Greeks thought that all matter was a mixture of four elements: earth, water, air and fire.

6. Position The location of any object.

7. Are you and your desk moving?

8. Frame of Reference The object or point from which movement is determined.

9. Is the sun setting or is the earth rising?

10. Earth is the most commonly used frame of reference.

12. Motion is a change in position relative to a frame of reference. Movement can only be measured with reference to something that is assumed to be fixed in place.