9/19 Lib Dub!
Pick a seat
Pick up a ruler and graph paper
The seat you seat in on Monday will be your
new seat. Anyone sitting towards back of class
will be moved forward.
9/22 We will be working on graphs this week
Pick a seat Anyone sitting towards back of class will
be moved forward.
Pick up disp v time graph WS II
Tests are graded. Corrections will be available Mon –Thu am
or pm. Test retakes Mon –Thu pm only
Corrections: Show all work on your own paper. Title Motion
Test Corrections, include name & period. Place corrections
paper clipped to your test and place in white period drawer.
When you have completed them turn them into the balck
basket on top on the white drawers. Tests are not to leave
my room 
9/22 We will be working trig
Test Tuesday
Pick a seat
The graphs…
Game
To begin, consider a car moving with a constant,
rightward (+) velocity of 10 m/s
What would a Position vs Time graph of this
motion, look like?
The slope of the line on a position-time graph is
the velocity of the object.
And the slope is…
Example A car moves in a straight line and its odometer readings
are plotted against time.
a. Find the speed of the car at points A and B.
B
x
40

= 0.5 m/s
80
t
Same for A and B
A
b. What is the car's average speed?

v = 0.5 m/s
c. What is its acceleration?
a = 0 m/s2
Compare contrast
No motion, constant velocity, and acceleration on DvT graph
Let’s compare the motions shown here
Compare the velocity of the red line to the…
Green line
Black line
Blue line
Orange line
And this trip shows?
Now consider a car moving with a changing, rightward
(+) velocity that is, a car that is moving rightward and
speeding up or accelerating.
And the graph’s shape is?
What if the shape of the graph is a curve?
A curve shows a
changing velocity
or acceleration.
Slope of a curve?
(3.0s, 18m) and (3.5s, 23m)
V1 = (23m -18m) = 10m/s
(3.5s -3.0 s)
(1.4s, 6m) and (2.0s, 9m)
V2= (9m - 6m) = 5 m/s
(2.0s - 1.4s)
The instantaneous velocity of an object at a certain
time is the slope of the position (displacement) versus
time graph at that time. It can be positive, negative,
or zero.
What shows the instantaneous speed in the car?
Compare contrast
No motion, constant velocity, and acceleration on VvT graph
The graphs…
Homework: Graphing Motion #1
NOT!! Be ready next class for
2 wkshts instead of one.
In this lab you will measure your
motion with a sonic motion detector.
The motion detector emits sound
waves and then detects them after they have
reflected off of some object (such as you or
your lab partners!). A computer then records
distance from the detector to the object as a
function of time. You will practice making and
interpreting position-time graphs.