Standard Strand 1: Motion
1. An object in motion changes
position relative to a reference
2. Speed measures how fast
3. Acceleration measures how fast
Choose an object in the class that is easy
Without writing what it is, write directions
to the object from your seat.
Share your directions with your tablemate.
Can he/she identify the original object?
Change your directions until your partner
locates your object.
Can you locate your partner’s object?
Modify the directions until you can.
What is position?
How do you describe a position?
How would your describe motion in terms
Speed Reference point
– Instantaneous Magnitude
Is a change in position with time (meaning
there is time interval involved - not
Is observed relative to a reference point:
– Are you in motion sitting quietly in your seat?
• From the viewpoint of the teacher? Your table
• From a viewpoint of an observer on the International
Point from which motion is
The most common reference point is the
Motion is said to be relative to a reference
– You are driving in a car. The driver is not
moving in comparison to you (RP1), but is
moving (as are you) relative to a person (RP2)
standing on the street who sees the change in
Reference Point Activity
The teacher tosses the ball in the air.
Describe the motion of the ball from the
teacher’s and the your position as
The teacher walks across the room
tossing a ball up and down. Describe the
balls motion - From both reference points.
What other terms are involved in
There is a change in position over time
which implies a distance has been
covered….Distance from position 1 to 2, 3,
4 and so on…..
There is a time interval.
What is the quantity known as distance/
Distance traveled over time
What is average speed?
What is constant speed?
What is instantaneous speed?
How would you graph speed?
Speed = distance/time
Our variable are: distance and time
Which is the “X” axis variable?
– Manipulated variable (independent
Which is the “Y” axis variable?
i What is slope?
The slope of a line is calculated by
dividing the change in Y (distance
between the Y’s) by the change in X
Y Yf - Yi RISE
X X f - Xi RUN
Slope : Rise (Y)/Run (X)
The slope of a line on a distance/time graph
indicates the speed (d/t) of the object.
Average speed: over time interval (speed/slope
Instantaneous speed: at a particular point
Constant speed: straight line
Slope = 0, no motion