1. Motion ONE DIMENSION POSITION: FRAME of REFERENCE 1 2 3 5 -1 4 +X1 2 3 5 -1 4 +X
TIME: STARTING POINT, define "t=0"
Need a meterstick!!!

2. Motion ONE DIMENSION MOTION IS RELATIVE
A boy sits in a moving train and plays with his toy train. Red arrows represent motion of the train and the toy train as seen by a man on the platform. Draw an arrow representing a motion of the toy train as seen by
Train motion
Toy train motion
the boy
the train driver
the toy train driver
Need a meterstick!!!

3. Motion ONE DIMENSION MOTION IS RELATIVE
Eugenia will skate across the floor after pushing off once (her pace does not change after she starts moving) and then drop the ball that she is holding in her hand. Use your knowledge of motion to predict where the ball will land relative to Eugenia before you view the video.
Hint:Think of how the ball will move with respect to Eugenia and how it will move with repsect to the floor.

4. Distance & Displacement
The total length of the path the object has traveled
DISPLACEMENT
The net CHANGE in position
An object starts at +1, moves right to x=+3, moves back left to +2, then finally moves right to +5, as shown. 1 2 3 5 -1 4 +X
Need a meterstick!!!
. The overall displacement is
Δx = 5 – 1 = +4 m
The overall distance is
2+1+3=6 m

5. Distance & Displacement
An object goes from one point in space to another. After it arrives at its destination, the size of its displacement is:
than the distance it traveled.
A: could be smaller or larger
B: always equal to
C: either greater than or equal to
D: either smaller than or equal to

6. Speed and Velocity Speed scalar: magnitude Velocity
vector: magnitude and direction
Need a battery-operated car, stopwatch, sugar packs

7. Speed and Velocity total distance Average Speed = scalar elapsed time
Average Velocity =
total displacement
elapsed time
vector

8. The cars started simultaneously at dot on the left and move to the right. The dots represent the locations of each car every second.
Car 1
Car 2
1. Where the cars ever next to each other?
2. Choose a reference frame associated with car 1. If there were a passengers in car 1, how would they describe the motion of car 2?
3. Choose a reference frame associated with car 2. If there were a passengers in car 2, how would they describe the motion of car 1?

9. Graphical representation
Motion Diagram
to represent, visualize and analyze motion
1. Draw dots to represent the positions of the object at equal time intervals
2. Point arrows in direction of motion, and use the relative length to indicate how fast the object is moving = -
3. Draw arrow to indicate how the arrows are changing.

10. Graphical representation
Motion Diagram
A car stops for a red light. When the light turns green, the car moves forward for 3s at increasing speed. The car then travels at constant speed for another 3s. Finally, when approaching another red light, the car steadily slows to stop during the next 3s.
Draw a motion diagram that describes this process
t=0
t=3s
t=6s
t=9s
= 0

11. Graphical representation
Graphs S
Clock reading t (s)
Position
S (m)
t0 = 0
t1 = 20
t2 = 40
t3 = 60
t4 = 80
t5 = 100
t6 = 120
S0 = 0
S1 = 100
S2 = 200
S3 = 300
S4 = 400
S5 = 500
S6 = 600 S, m
y = kx +b
100
200
300
400
500
600
S = kt +b
S = 5t +0
v=5m/s
Convert m/s into m/h 20 40 60 80
100
120
t, s

12. Graphical representation
Graphs S
640
Clock reading t (s)
Position
S (m)
t0 = 0
t1 = 20
t2 = 40
t3 = 60
t4 = 80
t5 = 100
t6 = 120
S0 = 640
S1 = 500
S2 = 360
S3 = 220
S4 = 80
S5 = -60
S6 = -200
Describe in words the motion of the biker:
In what direction does he go?
What is the starting point of his motion?
What is his speed?
Does it change?

13. Graphical representation
Graphs S
Construct a position-versus-clock reading graph for the bike trip.
Write a function of the graph.
Clock reading t (s)
Position
S (m)
t0 = 0
t1 = 20
t2 = 40
t3 = 60
t4 = 80
t5 = 100
t6 = 120
S0 = 640
S1 = 500
S2 = 360
S3 = 220
S4 = 80
S5 = -60
S6 = -200
S, m
t, s 20 40 60 80
100
120
200
300
400
500
600
S = t

14. Quiz Question
An ant crawling along the floor follows a semi-circular path, going half way around the circumference of a circle of radius R.
The distance traveled,
and the displacement of the ant,
are respectively:
A: p R and p R
B: 2 R and p R
C: p R and 2 R
D: p R and zero
E: none of these
Explain your answer!
The circumference is 2pR

15. Homework (due Wednesday)
Chapter 2. Problems (page 49)
Section 2.2 Velocity
# 2, 5, 6, 9, 12, 16, 17, 18
(make sure that you can solve all of the problems in this section!)