This document summarizes key concepts from Chapter 2 of a physics textbook on one-dimensional motion. It introduces displacement and velocity, explaining that displacement has direction while distance traveled does not. It defines average velocity and distinguishes between velocity and speed. The document then discusses acceleration, explaining how acceleration measures the rate of change in velocity and can be positive, negative, or zero. It introduces the concept of free fall due to gravity and the constant acceleration of gravity. Graphs of position versus time and velocity versus time are presented and kinematic formulas introduced.

1. Chapter 2
Motion in One
Dimension
Section 1
Displacement and Velocity

2. Motion
 Motion happens all around us in different directions and
different speeds.
 One – dimensional motion is the simplest form of motion.
 Example : Commuter train can move only forward and
backward along the straight track.

3. Frame of Reference
 Motion takes place over time and depends on
frame of reference.
 Frame of Reference – what you use to
measure changes in position.

4. Displacement
 Displacement is a
change in position. (Final
– Initial)
 Displacement is NOT the
same as distance
traveled.
 Displacement has a
direction.
 Right and Up is (+)
 Left and Down is (-)
Displacement

5. Displacement

6. Velocity
 Average Velocity is
displacement of an object
(Δx) divided by time
interval (Δt).
 Average Velocity can be
positive or negative
depending on the sign of
the displacement.
 If displacement is
negative, avg. velocity is
negative.
 Time interval is ALWAYS
positive

7. Guided Practice
 Open Books to pg. 44

8.  Velocity is not the same
as speed.
 Velocity describes motion
with direction and
magnitude (numerical
value);
 Speed ONLY has
magnitude.
 Ex: 55 m/s and 55 m/s
North
Velocity Vs. Speed

9. Velocity can be interpreted
graphically…

10. The motion of an object moving with constant
velocity will provide a straight-line graph of
position versus time. The slope of this graph
indicates the average velocity.

11. Section 2 Acceleration
Chapter 2
One
Dimensional
Motion

12. 2-2 Acceleration
 Acceleration measures the
rate of change in velocity.
 Has Magnitude & Direction.
 SI Units : m/s2
 Three ways to Accelerate:
 Object Speeding Up
 Object Slowing Down
 Object Changing Direction

13. Let’s Practice with Average
Acceleration...
 Sample Problem 2B
 Pg. 49 in your books.

14. Acceleration
 The slope and shape
of a graph plotting
velocity vs. time
describes the
object’s acceleration.
 When velocity on
graph is
increasing :
acceleration is positive
decreasing :
acceleration is
negative
constant : there is no
acceleration

15. Velocity Vs. Time Graphs

16. Kinematic Formulas

17. Formulas in Textbook
on Pg. 58

18. Section 3
Falling Objects
Chapter 2
One Dimensional
Motion

19. Free Fall
 Free fall is acceleration due to gravity.
 Free fall acceleration is constant.
 Magnitude of free fall is 9.81 m/s2
 Direction of free fall is directed downward.
 negative direction (-)
 Free fall is denoted with the symbol g. (Sometimes may
be ‘a’ for acceleration due to gravity)

20. Free Fall
 In a vacuum, in the absence of air resistance, all objects
fall at the same rate.

21. What goes up must come down.
What causes an
object that has been
thrown up into the air
to come back down?
Free-Fall Acceleration
due to gravity is
always directed
downward and pulling
an object towards
Earth’s surface.

22. Recall Information
 Remember we learned about a formula that can be
used to find final velocity at ANY displacement…
vf
2 = vi
2 + 2aΔx (time is not needed)
 We use this same formula but we change x to y
vf
2 = vi
2 + 2aΔy

23. Guided Practice
 Open books to pg. 63 Sample Problem 2F