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Initial section of our motion and forces unit. This presentation is used to deliver notes to the class.
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MOTIONAn object in motion changes position.
Jamal is in a car travelling north. He looks out of his window and thinks that the cars around him are moving slowly.
Ellen is in a car going south. She thinks that the northbound traffic is moving
quickly. Explain why Jamal and Ellen have different ideas about the motion of
the traffic. Maybe these terms will help: position,
motion, reference point, speed, frame of reference
MOTION
MOTION
Where is the ___________?NO POINTING!!!
The position of a place or an object is the location of that place or object
We describe the position of something by comparing it to where we are.
MOTION
Where is Rochester?
We usually describe the location of a city compared to that of another city.
A location to which you compare other locations is a reference point.
Longitude and latitude is based on reference points.
What is distance? (n) The extent or the amount of space
between two things. We measure distance depending on the
information that we want. Straight line distance (flight) vs. total
length of a certain path (hike) SI unit = meters (m) = 3.3 feet
MOTION
What is motion? (n) The change of position over time.
Do we need to see something move to know that motion has occurred?
No. We can assume based upon starting and ending positions.
MOTION
What is speed?
(n) A measure of how quickly or slowly an object changes position.
A faster object moves farther than a slower object over the same amount of time.
MOTION
If you sit still in a chair, are you moving?
It depends on the position and motion of the person watching you.
If inside the room, no, you are not moving.
If in space, yes, you are moving. This is known as frame of reference.
MOTION
Frame of reference aka relative motion Consider this:
You are sitting directly behind a bus driver.
- Is the driver moving?
- Is the street sign moving?
An observer is on the sidewalk.
- Is the driver moving?
- Is the street sign moving?
MOTION
REVIEW QUESTIONS What do you need to describe an
object’s location? Describe how your position changes as
you jump over an object. Give an example of how the apparent
motion of an object depends on the observer’s motion.
MOTION