Motion
Introduction
1
Frozen Time
2
Frozen Time
3
Motion Diagram
4
Motion Diagram
5
Motion Diagrams
6
Linear Functions
1.Find the equation of the red trend line in the form y=mx+b, where x is
years since 2000 and y is concentration of CO2 in ppm.
CO2, Mauna Loa
CO2 Concentration (ppm)
390
385
380
375
370
365
2000
2001
2002
2003
2004
2005
2006
2007
2008
time (years)
7
Chapter 1. Reading Quizzes
8
What is a “particle”?
A. Any part of an atom
B. An object that can be represented as a mass at
a single point in space
C. A part of a whole
D. An object that can be represented as a single
point in time
E. An object that has no top or bottom, no front or
back
9
What is a “particle”?
A. Any part of an atom
B. An object that can be represented as a mass at
a single point in space
C. A part of a whole
D. An object that can be represented as a single point
in time
E. An object that has no top or bottom, no front or
back
10
What quantities are shown on a complete
motion diagram?
A. The position of the object in each frame of the film,
shown as a dot
B. The average velocity vectors (found by connecting
each dot in the motion diagram to the next with a
vector arrow)
C. The average acceleration vectors (with one
acceleration vector linking each two velocity
vectors)
D. All of the above
11
What quantities are shown on a complete
motion diagram?
A. The position of the object in each frame of the film,
shown as a dot
B. The average velocity vectors (found by connecting
each dot in the motion diagram to the next with a
vector arrow)
C. The average acceleration vectors (with one
acceleration vector linking each two velocity
vectors)
D. All of the above
12
An acceleration vector
A. tells you how fast an object is going.
B. is constructed from two velocity vectors.
C. is the second derivative of the position.
D. is parallel or opposite to the velocity vector.
E. Acceleration vectors weren’t discussed in this chapter.
13
An acceleration vector
A. tells you how fast an object is going.
B. is constructed from two velocity vectors.
C. is the second derivative of the position.
D. is parallel or opposite to the velocity vector.
E. Acceleration vectors weren’t discussed in this chapter.
14
The pictorial representation of a physics
problem consists of
A.
B.
C.
D.
E.
a sketch.
a coordinate system.
symbols.
a table of values.
all of the above.
15
The pictorial representation of a physics
problem consists of
A.
B.
C.
D.
E.
a sketch.
a coordinate system.
symbols.
a table of values.
all of the above.
16
Motion Diagram Concept Questions
17
Three motion diagrams are shown.
Which is a dust particle settling to the
floor at constant speed, which is a ball
dropped from the roof of a building, and
which is a descending rocket slowing to
make a soft landing on Mars?
A. (a) is ball, (b) is dust, (c) is rocket
B. (a) is ball, (b) is rocket, (c) is dust
C. (a) is rocket, (b) is dust, (c) is ball
D. (a) is rocket, (b) is ball, (c) is dust
E. (a) is dust, (b) is ball, (c) is rocket
18
Three motion diagrams are shown.
Which is a dust particle settling to the
floor at constant speed, which is a ball
dropped from the roof of a building, and
which is a descending rocket slowing to
make a soft landing on Mars?
A. (a) is ball, (b) is dust, (c) is rocket
B. (a) is ball, (b) is rocket, (c) is dust
C. (a) is rocket, (b) is dust, (c) is ball
D. (a) is rocket, (b) is ball, (c) is dust
E. (a) is dust, (b) is ball, (c) is rocket
19
A particle moves from position 1 to
position 2 during the interval ∆t. Which
vector shows the particle’s average
velocity?
20
A particle moves from position 1 to
position 2 during the interval ∆t. Which
vector shows the particle’s average
velocity?
21
A particle undergoes acceleration a while
moving from point 1 to point 2. Which of
the choices shows the velocity vector v 2 as
the object moves away from point 2?
22
A particle undergoes acceleration a while
moving from point 1 to point 2. Which of
the choices shows the velocity vector v 2 as
the object moves away from point 2?
23
Graphical Analysis of Motion Concept Questions
24
Which position-versus-time graph represents the
motion shown in the motion diagram?
25
Which position-versus-time graph
represents the motion shown in the
motion diagram?
26
Which velocity-versus-time graph goes
with the position-versus-time graph on
the left?
27
Which velocity-versus-time graph goes
with the position-versus-time graph on
the left?
28
The graph of position
versus time for a car is
given below. What can
you say about the
a) it speeds up all the time
b) it slows down all the time
c) it moves at constant velocity
d) sometimes it speeds up and
sometimes it slows down
velocity of the car over
time?
x
t
e) not really sure
a) it speeds up all the time
The graph of position
b) it slows down all the time
versus time for a car is
c) it moves at constant velocity
given below. What can
d) sometimes it speeds up and
sometimes it slows down
you say about the
e) not really sure
velocity of the car over
time?
The car moves at a constant velocity
x
because the x vs. t plot shows a straight
line. The slope of a straight line is
constant. Remember that the slope of x
versus t is the velocity!
t
a) it speeds up all the time
The graph of position
vs. time for a car is
given below. What can
you say about the
b) it slows down all the time
c) it moves at constant velocity
d) sometimes it speeds up and
sometimes it slows down
e) not really sure
velocity of the car over
time?
x
t
The graph of position
a) it speeds up all the time
b) it slows down all the time
vs. time for a car is
c) it moves at constant velocity
given below. What can
d) sometimes it speeds up and
sometimes it slows down
you say about the
e) not really sure
velocity of the car over
time?
The
car slows down all the time
because the slope of the x vs. t graph
is diminishing as time goes on.
Remember that the slope of x vs. t is
the velocity! At large t, the value of the
position x does not change, indicating
that the car must be at rest.
x
t
Which position-versus-time graph goes with
the velocity-versus-time graph at the top? The
particle’s position at
ti = 0 s is xi = –10 m.
33
Which position-versus-time graph goes with
the velocity-versus-time graph at the top? The
particle’s position at
ti = 0 s is xi = –10 m.
34
a) decreases
Consider the line labeled
b) increases
A in the v versus t plot.
c) stays constant
How does the speed
d) increases, then
decreases
change with time for line
e) decreases, then
increases
A?
v
A
t
B
a) decreases
Consider the line labeled
b) increases
A in the v versus t plot.
c) stays constant
How does the speed
d) increases, then
decreases
change with time for line
e) decreases, then
increases
A?
v
A
t
B
In case A, the initial
velocity is positive and the
magnitude of the velocity
continues to increase with
time.
a) decreases
Consider the line labeled
b) increases
B in the v versus t plot.
c) stays constant
How does the speed
d) increases, then
decreases
change with time for line
e) decreases, then
increases
B?
v
A
t
B
a) decreases
Consider the line labeled
b) increases
B in the v versus t plot.
c) stays constant
How does the speed
d) increases, then
decreases
change with time for line
e) decreases, then
increases
B?
v
A
t
B
In case B, the initial velocity is positive
but the magnitude of the velocity
decreases toward zero. After this, the
magnitude increases again, but
becomes negative, indicating that the
object has changed direction.
Which velocity-versus-time graph or
graphs goes with this acceleration-versustime graph? The particle is initially moving
to the right and eventually to the left.
39
Which velocity-versus-time graph or
graphs goes with this acceleration-versustime graph? The particle is initially moving
to the right and eventually to the left.
40
When throwing a ball straight
a) both v = 0 and a = 0
up, which of the following is
b) v  0, but a = 0
true about its velocity v and its
c) v = 0, but a  0
acceleration a at the highest
d) both v 0 and a  0
point in its path?
e) not really sure
When throwing a ball
a) both v = 0 and a = 0
straight up, which of the
b) v  0, but a = 0
following is true about its
c) v = 0, but a  0
velocity v and its acceleration a
d) both v 0 and a  0
at the highest point in its path?
e) not really sure
At the top, clearly v = 0 because the ball has
momentarily stopped. But the velocity of the
ball is changing, so its acceleration is definitely
not zero! Otherwise it would remain at rest!!
y
The ball rolls up the ramp, then back
down. Which is the correct acceleration
graph?
43
The ball rolls up the ramp, then back
down. Which is the correct acceleration
graph?
44
Rubber Ball I
You drop a rubber ball. Right after it leaves your hand and
before it hits the floor, which of the above plots represents
the v vs. t graph for this motion?
(Assume your y-axis is
pointing up).
v
a
v
c
t
t
v
b
v
t
d
t
Rubber Ball I
You drop a rubber ball. Right after it leaves your hand
and before it hits the floor, which of the above plots
represents the v vs. t graph for this motion?
(Assume
your y-axis is pointing up).
v
a
v
c
t
t
v
b
v
t
d
t
Rubber Ball II
You toss a ball straight up in the air and catch it again.
Right after it leaves your hand and before you catch it,
which of the above plots represents the v vs. t graph for
this motion? (Assume your y-axis is pointing up).
v
v
a
t
c
t v
v
b
d
t
t
Rubber Ball II
You toss a ball straight up in the air and catch it again.
Right after it leaves your hand and before you catch it,
which of the above plots represents the v vs. t graph for
this motion? (Assume your y-axis is pointing up).
v
v
a
t
c
t
v
b
d
t
v
t
Rubber Ball III
You drop a very bouncy rubber ball. It falls, and then it
hits the floor and bounces right back up to you. Which
of the following represents the v vs. t graph for this
motion?
v
v
a
b
t
v
b
t
t
d
v
t
Rubber Ball III
You drop a very bouncy rubber ball. It falls, and then it
hits the floor and bounces right back up to you. Which
of the following represents the v vs. t graph for this
motion?
v
v
a
b
t
v
b
t
t
d
v
t