The Project Physics Course
Tests
Concepts of Motion
1
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The Project Physics Course
Tests
Concepts of Motion
1
Digitized by the Internet Archive in
2010 with funding from
R James
Rutherford
http://www.archive.org/details/testbooklet1conc00fjam
The
Project Physics
Course
Tests
UNIT
1 Concepts
of
Motion
Distributed by
A Component of the
Holt,
Project Physics Course
New York-Toronto
Rinehart and Winston, Inc.
This publication is one of the many instructional materials developed for the Project Physics Course. These materials include Texts, Handbooks, Teacher Resource Books, Readers, Programmed Instruction Booklets, Film Loops, Transparencies, 16mm films and laboratory equipment. Development of the course has profited from the help of
many colleagues
Directors
listed in the text units.
of Harvard
Project Physics
Gerald Holton, Department of Physics, Harvard University
James Rutherford, Chairman of the Department New York University, New York Fletcher G. Watson, Harvard Graduate School of F.
of Science
Education,
Education
Picture Credit
LIFE MAGAZINE,
Cover photo:
F. Miller,
Copyright
1970, Project Physics
(c)
All Rights Reserved
ISBN: 0-03-084815-6 3456789 039 9876543 Project Physics
is
a registered trademark
©
Time,
Inc.
TEST A
Directions
This test consists of fifteen multiple-choice questions and six problem-and-essay questions, divided
Answer ALL multiple-choice questions by marking the letter corresponding to the Answer THREE of the problem-and-essay questions from Group One and ONE from Group Two. Spend about 15 minutes on the multiple-choice questions, 5 minutes on each of the problem-and-essay questions from Group One and 10 minutes on the problem-and-essay question from Group Two.
into
two
groups.
one best answer.
The numerical
some
values of
physical constants
and equations that may be useful
in the test are
and acceleration vectors for a car
at five separate
given on the last page of this booklet.
1
.
The arrows show the
direction of the velocity
instants of time.
Which diagram
applies to the car while
turning a comer?
it is
7=0
2.
Several cars are racing
racing car after
3.
it
on an oval
track.
Which of the following statements
correct for every
when it crossed the starting line. when it crossed the starting line.
the same as
A.
Its
acceleration
B.
Its
speed
C.
Its
displacement from the starting line
D.
Its
acceleration has not changed since
E.
Its
velocity has not changed since
is
is
completes exactly one lap of a race?
is
the same as
ALL EXCEPT ONE
it
is
it
zero.
crossed the starting line.
crossed the starting line.
of the following require the application of a net force. Which one
exception?
from a state of rest to state of motion motion at a constant velocity
A.
to change an object
B.
to maintain an object in
C.
to change an object's speed without changing
D.
to maintain an object in uniform circular motion
E.
to change an object's direction of motion without changing
its
direction of
motion
its
speed
is
the
4.
Which one of the following statements correctly describes a
satellite orbiting
A.
The
B.
There
C.
The velocity of the satellite is constant. The satellite must fall back to earth when its fuel is gone. The satellite is always accelerating toward the earth.
D. E.
and velocity of the satellite no force acting on the satellite.
acceleration is
are in roughly the
same
about the earth?
direction.
Questions 5 and 6 refer to the graph at the right.
5.
The magnitude of the celeration
is
ac-
greatest in the
time interval
6.
A.
a to
B.
c to e.
C.
e to
D.
gtoi.
E.
i
g.
to k.
The speed A.
7.
c.
is
time
greatest at the time corresponding to point
c.
B.
g.
C.
h.
D.
i.
E.
k.
The following rate
is
are diagrams
constant and
is
which represent stroboscopic photographs of a
the same for
all
12 Which of the photographs could be produced with a stationary A.
None
B.
1 only
C.
2 only
D.
1
E.
and 2 only 1,2 and 3
ball.
The strobe
three pictures.
3
ball
and a moving camera?
Questions 8 and 9 refer to the graph at the right and statement below. The graph shows the positions of five sprinters near the
end of an 800-meter
The average speed of sprinter C in the time period 127 second to 129 second from the start
A.
was approximately
race.
Questions 11 and 12 refer to the following, which
is
a hypothetical report submitted
by an
astro-
naut about a space maneuver intended to link two capsules:
"At 5:01:00 A.M. we
activated
Rocket Z-4 for 10 seconds. The thrust gauge showed that the
2 estimated a velocity toward the target 3 expected to touch the target vehicle in 300 seconds, at 5:06:10.
1
rocket produced a force of 77 newtons. Accordingly, vehicle of 4 meters/second.
We
we
4 Actually,
11.
we touched
at 5:06:28."
Which of the sentences above
gives the result of a
computation done by the astronaut that
in-
volved the use of Newton's second law? 1 only
A. 12.
C.
3 only
4 only
D.
E.
2,
3 and 4 only
Which of the sentences above describes how the astronaut changed conditions to perform the maneuver? 1 only
A.
13.
2 only
B.
A child is riding on a he
is
at point P,
4 only
B.
C.
5 only
1
merry-go-round, as shown at the right.
which
set of vectors
shows the direction of
ocity V, his acceleration a and the centripetal force
A.
D.
F
and 4 only
When his vel-
acting on
him?
E.
1
and 5 only
PROBLEM-AND-ESSAY QUESTIONS Group One Answer 1.
A
THREE
of the following four questions.
30-kilogram block
lies
on a
frictionless table,
and
is
connected to a 10-kilogram block by a
rope passing over a frictionless pulley, as shown in the diagram. 30 kg a)
What
is
V///A
the acceleration of the 10-kilogram
;^
block? b)
What
is
the acceleration of the 30-kilogram
block? 10 kg 2.
A car accelerates away
from a
stoplight.
Use
this
example of a moving object to explain the
difference between average speed and instantaneous speed.
3.
The diagram below per second.
On
this
motion of a ball as if it were recorded by a camera whose whose only source of light was a stroboscopic lamp flashing 10 times
illustrates the
shutter remained open and
diagram 1.0 centimeter represents 1.0 centimeter
was the acceleration of the
in the laboratory.
What
ball?
direction of
start
motion
\
o o
4.
Find Av, where
Av
o
= Vj - Vi
Group Two Answer 5.
ONE
of the following two questions.
Galileo held that the proper language vidth which to describe nature
is
mathematics.
our understanding of natural phenomena aided by describing what we observe terms?
in
How
is
mathematical
6.
A man
goes for a walk. Write a description of his motion that includes numerical values of time, distance and speed, based on the information contained in the graph below.
20 time (minutes)
30
TEST B
Directions
This test consists of fifteen multiple-choice questions and six problem-and-essay questions, divided into
two groups. Answer
one best answer. Answer
ALL multiple-choice questions by marking the letter corresponding to the THREE of the problem-and-essay questions from Group One and ONE
from Group Two. Spend about 15 minutes on the multiple-choice questions, 5 minutes on each of the problem-and-essay questions from
Group One and 10 minutes on the problem-and-essay question
from Group Two.
The numerical values of some physical constants and equations that may be given on the last page of this booklet.
Questions 1 and 2 refer to the figure at right, which
shows the positions of
five
800
runners near the end of an
800-meter race.
1.
Which A.
sprinter
was ahead
after exactly
127 seconds?
795
useful in the test are
.
4.
'
Which of the following four diagrams represents the acceleration of a golf
a
5.
ball the instant after
leaves the face of a golf club?
it
An
ice skater gives a
sudden push to a sled that sends
following statements (assume friction
The force exerted on the
1
is
sliding
away from him. Consider the
negligible).
by the skater
sled
it
=
is
equal in magnitude to the force exerted on
the skater by the sled.
During the push the acceleration of the skater
2.
is
equal in magnitude to the acceleration of
the sled.
The skater
3.
will accelerate for
Which of the statements A.
6.
is
true
if
the same length of time as the sled.
the skater and the sled have the same mass?
1 only
B.
2 only
C.
3 only
D.
2 and 3 only
E.
1,2 and 3
A child is riding on a merry-go-round that A.
constant velocity.
B.
constant acceleration.
is
rotating at a constant rate.
C.
constant speed.
D.
constant acceleration and speed
E.
constant velocity, acceleration and speed
The
In the graph at the right, the
magnitude of the acceleration is
greatest in the time interval
A.
a to
B.
c to e.
C.
e to
D.
g to
E.
i
c.
g.
^^
y^ a
c
'
d I
I I
I !
!
/
>v
!
X/ / rv g/
i.
to k. time
!
child has
8.
9.
10.
ALL EXCEPT ONE
of the following require a net unbalanced force. Which
A.
to set into motion an object which
B.
to maintain an object in a state of constant velocity
C.
to maintain an object in a state of uniform circular motion
D.
to stop a
E.
to change an object's direction of
Tlie distance
is initially
is
the exception?
at rest
moving object
d traveled by an object
moving
is
motion while keeping
speed constant
given by the equation d =
A.
is
B.
has a constant velocity.
C.
starts
D.
is
from rest and accelerates uniformly. thrown upward.
E.
is
thrown downward.
This test paper
its
V2 at^,
when the
object
in a circle.
sitting at rest
is
on your desk. Which of the following statements best describes
this situation?
11.
A.
There are no forces acting on your paper.
B.
C.
Your paper Your paper
D.
There are
A satellite is in statements
A.
The
B.
There
C.
The The The
D. E.
12.
is
any coordinate system. no force on the desk. many forces acting on your paper, but they balance each other. is
at rest in
exerts
orbit
around the earth, hi the absence of
acceleration and velocity of the satellite is
air friction,
no force acting on the
velocity of the satellite
is
Eire
in
constant.
back to earth when
satellite
must
satellite
always accelerates towards the earth.
fall
approximately the same direction.
satellite.
its fuel is
gone.
you must choose between two hypotheses, which of the following
If
which of the following
necessarily true?
lecting hypothesis 1 rather than hypothesis 2?
more
agreement with the observed
A.
Hypothesis 1
B.
Hypothesis 1 contains more mathematics.
C.
Hypothesis 1
is
newer.
D.
Hypothesis 1
is
more
E.
Several people think hypothesis 1
is
in
easily
facts.
understood. is
more
likely to be correct.
is
the best reason for se-
13.
A rock is thrown into the air. changes with time while
v time
A
^
it is
Which graph represents how the magnitude of
in the air? (Neglect air resistance.)
its
acceleration
2.
Consider the motion of a flare dropped from an airplane flying at constant velocity. Describe this
3.
4.
motion
What
An
is
as seen
by observers
in the airplane
and on the ground.
the difference between the concepts "weight" and "mass"?
object resting on a level frictionless surface on the earth
equEil to its weight.
What
is
the magnitude of
its
is
subjected to a horizontal force
acceleration?
Group Two Answer 5.
ONE
of the following two questions.
Joe and Louis are arguing about uniform acceleration. Joe says that acceleration means "the longer
you go, the faster you go." Louis you go."
states that acceleration
means "the
farther
you
go,
the faster
6.
a)
Present their points of view in terms of an equation or equations.
b)
Who
is
right
and why?
Galileo approached scientific problems in
Two
ways different from Aristotle and the
of these differences are listed below. Select one and explain
why you
Scholastics.
think
it
was impor-
tant to the development of physics.
and observation must be quantitative, not
a)
insistence that experiment
b)
abstraction from real situations to idealized ones that
just qualitative.
show the laws of nature
in their
simplest form.
11
TEST C
Directions
Answer
ALL
forty multiple-choice questions
by marking the
letter
corresponding to the one best
answer.
The numerical values of some physical constants and equations that may be given on the last page of this booket.
1.
An
experiment yielded the data given in the table and graph below.
t
useful in the test are
H
The arrows drawn below represent the
velocity vectors of a Boeing
707
jet at three successive
times.
H
We may
conclude that the
jet
was
A.
changing direction.
B.
speeding up.
C.
slowing down.
D.
maintaining a constant velocity.
.06
Questions 4 and 5 refer to the following state-
ment and graph: The graph relationship
at the right
between the time and the
distance
total dis-
traversed
tance traversed by a glider moving on a nearly frictionless air track. Points P2
,
P4 and P^ rep-
The smooth curve drawn through
resent the experimental measurements.
dotted curve these points.
is
a
.
shows the
—— I
6.
Two men
level floor as indicated in the diagram below. The drawn proportional to the magnitude of the force each man exerts on
push on a box resting on a smooth
lengths of the arrows are
the box.
In the diagram below, which arrow indicates the direction in which the
box
will start to
move?
A
7.
A satellite is in a circular orbit aroimd a radius of the orbit its
acceleration?
A.
R are known. Which
planet.
The
satellite's
period of revolution T, and the
of the following equations must you use to compute
10.
In
ALL EXCEPT ONE
of the following situations, an object
is
being accelerated. Which one
is
the exception?
A. B.
C.
D. E.
The The The The The
object changes direction without changing speed. object changes speed without changing direction. object maintains speed and direction. object maintains uniform circular motion. object
moves
in the trajectory of a projectUe.
Questions 11 and 12 refer to the following situation.
During a planned maneuver in space
flight, a free-floating
ment package. The mass of the astronaut 11.
astronaut pushes a free-floating instru-
greater than that of the instnmient package.
The force exerted by the astronaut on the instrument package A.
is
equal to the force exerted by the package on the astronaut.
B.
is
greater than the force exerted
by the package on the astronaut. than the force exerted by the package on the astronaut.
C.
is
less
D.
is
equal to zero.
E.
may
be greater than,
naut; one cannot
12.
is
less than,
or equal to the force exerted by the package on the astro-
with the information given here.
tell
During the push A.
the magnitude of the acceleration of the astronaut
is
greater than that of the instrument
is
smaller than that of the instrument
package. B.
the magnitude of the acceleration of the astronaut
package.
13.
C.
neither astronaut nor instrument package
D.
the accelerations of each are equal in magnitude but opposite in direction.
E.
the accelerations of each are equal in magnitude and in the same direction.
In
Two New
erated,
when
accelerated.
Sciences Salviati, speaking for Galileo, defines "a motion to be uniformly accelstarting
from
speed." This definition
A.
is
is
rest
it
acquires during equal time intervals, equal increments of
important because
it
convinces Simplicio, the spokesman for Aristotelian physics.
way
B.
corresponds closely to the
C.
explains the cause of acceleration of falling objects.
D.
is
correct regardless of the air resistance of falling objects.
E.
is
the only definition that can be tested by experiment.
real objects fall near the surface
of the
esirth.
15
14.
ALL EXCEPT ONE of the following statements would of time.
One second
Which one
is
be operational definitions of one second
the exception?
is
more time than
A.
a
B.
the shortest unit of time.
little
there
is
C.
1/86,400 of the time
D.
the length of a time interval a
it
between the pulsebeats of most people.
takes the earth to little
make one
shorter than
it
rotation about
its axis.
takes a student to answer this question.
Questions 15 and 16 refer to the following statement.
Scientists
on the imaginary planet
Q have
defined a unit of length, the "lar," to be the distance
between two mountain peaks on the surface of the planet. The unit of time on the planet the "tik" and
15.
16.
What
would express acceleration on planet
units
A.
lar/tik
B.
lar /sec
C.
lar ^ /sec
D.
tik/lar^
E.
lar/tik^
If
the distance between the
average speed be
17.
A.
0.2 lars/tik
B.
0.1 tiks/lar
C.
5 tiks/lar
D.
5 lars/tik
E.
100
if
cities
you made the
Q if acceleration
Zytropolis and Elany on planet trip in
100
were defined as
Q is
20
lars,
at the right represents the distance traveled
by
an automobile as a function of time. The instantaneous speed at the time corresponding to point S
is
best apdistance
proximated by the slope of a straight
line
drawn between
points
A.
S and T.
B.
O and S. R and S. R and T. R and U.
C.
D. E.
16
is
called
it is
on earth?
what would your
tiks?
tiks/lar
The graph
Q
defined as the average interval between pulsebeats of the king.
is
time
18.
A subway
A boy
subway station, the dime hits the floor. Later, when the car high, constant speed, he flips the dime again car
is
at rest in a
sitting in the car flips a
dime into the
air;
moving over a straight, level section of track at a same way. Where does the dime hit
is
in exactly the
the floor?
A. B. C.
same spot on the floor ahead of where it hit before. behind where it hit before.
at the
as before.
Questions 19 and 20 refer to the following statements concerning Galileo's work with balls rolling
down
inclined planes.
work
This
led to the acceptance of the idea that falling objects accelerate
uniformly. The quotations are from
1.
speed during
If
fall
Two New
Sciences.
—d
increases with time,
is
constant.
t^
2.
"We took
a piece of
wooden
finger breadths thick. In
3.
scantling,
about 12 cubits long, half a cubit wide, and three
top edge we cut a straight channel."
"Having raised the scantling in a sloping position by raising one end some one or two cubits
above the other, we 4.
its
"We always found
let
the ball roll
down
the channel."
that the distances traversed were to each other as the squares of the
times."
5.
Since for a rolling ball
2
is
constant,
V
19.
20.
3
is
constant for a falling ball also.
1/
Which of the statements are assumptions made by Galileo? only
A.
1
B.
4 only
C.
5 only
and 4 only
D.
1
E.
4 and 5 only
Which statement presents experimental A.
1 only
B.
4 only
C.
5 only
D.
2 and 3 only
E.
1
results?
and 5 only
17
Questions 21 and 22 refer to the following graph.
time
21.
22.
The
greatest distance
A.
a and
c.
B.
c
and
e.
C.
e
D.
g
E.
i
V
is
23.
between times corresponding to points
A.
a and k,
B.
c
C.
and g. g and i. i and k.
E.
and
e.
e
A cart, initially sents
traveled between the times corresponding to points
and g. and i. and k.
greatest
D.
is
how the
at rest,
is
pulled with a constant, unbalanced force.
speed of the cart changes with time?
Which graph best
repre-
For questions 24 and 25 use the following figures which represent stroboscopic photographs of a moving ball. The strobe rate is constant and is the same for all three "photographs."
24.
Which of the "photographs" could have been produced with the camera
in
motion and the
ball
fixed in position?
25.
A.
none
B.
1 only
C.
2 only
D.
1
E.
1,
If
and 2 only 2 and 3
the camera
is
fixed in position, which of the "pictures"
show a
ball
being acted upon by a net
unbalanced force?
26.
27.
A.
1 only
B.
3 only
C.
1
D.
and 3 only 2 and 3 only
E.
1,
2 and 3
Which of the following increases with time A.
instantaneous velocity
B.
average velocity
C.
acceleration
D.
direction
E.
displacement
A sprinter reaches top speed 3
if
an object moves with uniform velocity?
seconds after the start of a race. In those 3 seconds, he moves
18 meters. Assume that he accelerates uniformly. What A.
2 meters/sec^
B.
3 meters/sec^
C.
4 meters/sec^
D.
7 meters /sec^
E.
18 meters /sec ^
is
his acceleration?
19
Questions 28 and 29 refer to the following statement and table:
Main Street
in Centerville
between the numbered
is
crossed by streets called 1st St.,
2nd
St.,
3rd St.
...
46th
St.
Blocks
streets are equally long.
Five cars are traveling along Main Street, and their locations are recorded at five-minute invervals, as
shown
in the following table:
31.
when each
is
moving with constant speed on
of the following conditions must apply
if
one
the motion of a bicyclist seen from a passing car
a straight, horizontal road
32.
ALL EXCEPT ONE d = A. B.
C.
D. E.
33.
An
V2 at^
.
Which one
is
The motion must be free fall. The acceleration must be constant in magnitude. The initial velocity of the body must be zero. Displacement must be measured from the point where motion Acceleration must be constant in direction.
80-kilogram fireman slides
tional force of
down
to use the equation
begins.
a pole in a fire station. His grip
240 newtons opposing
toward the floor below? A.
is
the exception?
his fall.
What
is
on the pole causes a
fric-
the approximate value of his acceleration
36.
Just before the end of a 25-lap auto race, the five
leading cars
moving
are in the positions
in a counter-clockwise direction
shown
the following statements
in the diagram.
is
necessarily true?
traveling with the smallest speed.
A.
Car 5
B.
Car 2 can cross the finish line without changing
is
direction of travel
Which of
velocity.
Car 4 can cross the finish line without changing speed.
37.
finish line
D.
Car 1
E.
All 5 cars are traveling with the
will finish first.
Measurements made on a
ball rolling
same
velocity.
down
a hill of
unknown shape provided
data:
Instantaneous
Time
Speed m/sec
sec
1
6
2
12
3
18
4
20
5
22
6
24
Which of the following diagrams could represent the shape of the hiU?
22
the following
h
38.
Which of the following
pairs of vectors has the resultant of largest
H
39.
A.
pair
A
B.
pair
C.
pair
B C
D.
pair
D
E.
pair
E
The arrows
in the diagrams
—
I
I
I
magnitude?
—
H
H
—— I
I-
below show the directions of the velocity and acceleration vectors
that apply to a car at five separate instants of time.
v =
a =
ALL EXCEPT ONE Which
40.
is
of the diagrams above
show an
instant at
which the velocity
is
changing.
the exception?
A
A.
diagram
B.
diagram B
C.
diagram C
D.
diagram
E.
diagram E
D
A satellite is in a circular orbit around the earth.
Which of the following statements must be
true? 1.
2. 3.
A.
1 only
B.
2 only
C.
1
D.
2 and 3 only
E.
1,2 and 3
The speed is constant. The velocity is constant. The period is constant.
and 3 only
23
TEST D
Directions
This test consists of eight questions in two groups. Answer only FOUR of the five questions in Group One, and only TWO of the three questions in Group Two. Spend about 5 minutes on each of the questions from Group One, and 10 minutes on each of the questions from Group Two.
The numerical values of some physical constants and equations that may be useful given on the last page of this booklet.
in the test are
Group One
Answer
1.
FOUR of the five questions in this group.
A satellite is in a circular orbit. ation, its velocity
2.
and
its
Describe the force acting on the
At time zero, a boy mounted a bicycle and rode for 3 seconds.
He continued
off, accelerating
at constant speed for
abruptly. Plot the boy's motion
3.
satellite,
the
satellite's acceler-
speed.
uniformly at 2 meters /second^
an additional 5 seconds and then stopped
on a speed-versus-time graph.
List three experimental techniques
now
available for the study of
motion that were not
avail-
able to Galileo in 1632.
24
A
= B + C + D.
4.
Find A, where
5.
To an Aristotelian, it seems clear that a force is necessary to maintain uniform motion. Comment on this statement from the point of view of a Newtonian.
Group Two
TWO of the three questions in this group.
Answer
6.
An
airplane
titude of
is
flying horizontally over the ocean at a speed of
2000 meters. The
pilot drops a
a)
How many seconds after release
b)
At what distance from point
flare.
(Neglect
200 meters /second and
at
an
al-
air resistance.)
does the flare hit the water?
P, directly
under the point of release, does the
flare strike
the water?
Acceleration
is
the rate of change of speed. Instantaneous acceleration
time graph at a point. Suppose
b)
What What
c)
How can we
a)
8.
In
is
fall.
call
is
the slope of a speed-
the rate of change of acceleration surge.
the algebraic expression defining average surge?
are the units of surge?
Two New
free
we
calculate instantaneous surge?
Sciences, Galileo uses the character Salviati to present his
At one point
own
views concerning
in the discussion Salviati states:
then we take two bodies whose natural speeds are different,
it is clear that on uniting the two, more rapid one will be partly retarded by the slower, and the slower will be somewhat hastened by the swifter. ... But if this is true, and if a large stone moves with a speed of, say, eight while a smaller moves with a speed of four, then when they are united, the system will move with a speed of less than eight; but the two stones when tied together make a stone larger than that which before moved with a speed of eight. Since the heavier body moves with less speed than the hghter .... you see how, from the premise that the heavier body moves more rapidly than the lighter one, I infer that the heavier body moves more slowly.
If
the
Salviati
based the preceding argument on several assumptions that are not necessarily valid.
a)
State one of these assumptions.
b)
Consider that this assumption
c)
Based on your assumption, what conclusions can be drawn regarding the rate of
is
not
valid.
Propose a more appropriate assumption. fall
of
the two stones that are tied together?
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