http://www.ck12.org Chapter 4. Motion and Forces
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/5019Q: What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell that
the bus is moving?
A: Your frame of reference might be the trees and other stationary objects across the street. As the bus goes by, it
momentarily blocks your view of these objects, and this helps you detect the bus’ motion.
Summary
- Motion is defined as a change of position.
- How we perceive motion depends on our frame of reference. Frame of reference refers to something that is
not moving with respect to an observer that can be used to detect motion.
Vocabulary
- frame of reference: Something that is not moving with respect to an observer that can be used to detect
motion. - motion: Change in position.
Explore More
Do the frame of reference activity at the following URL. Watch the introduction and then do the nine trials. Repeat
any trial you answer incorrectly until you get the correct answer.
http://www.amnh.org/learn/pd/physical_science/week2/frame_reference.html
Review
- How is motion defined in science?
- Describe an original example that shows how frame of reference influences the perception of motion.