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AP PHYSICS STUDY SKILLS (thanks
to Dolores Gende)
Physics
is not a spectator sport. You cannot expect to acquire the understanding you
need to do well on an AP Exam by merely attending class and listening to the
teacher. It requires your active participation in the learning process. You
should ask questions such as "Why do we think this?" and
"What would happen if we did this?" and if you can't answer them,
seek the help of your physics teacher or other students.
Having
the opportunity to answer these questions by exploring phenomena and
conducting experiments in the laboratory can often help you internalize the
concepts and make them more concrete. Some computer simulations that allow
you to set up hypothetical physical situations and observe the results of
changing various
quantities
in the situations can also be helpful in developing conceptual
understanding.
When
studying physics from a textbook, it is a good idea to have paper and pencil
with you. You could review by working the details of solutions
to example problems on your own. If you have completed the problems assigned
by your teacher for homework and are still not sure of your understanding of
the material, try some of the unassigned problems in the book on the same
topic.
Many
students have the impression that physics is merely a list of formulas to be
memorized and recalled at the proper time. Of course, formulas and equations
are important in physics, but that is because physics is a science that
deals with principles that can be expressed quantitatively. The equations
are merely a way of expressing these principles. A feel for the physical
reality behind the equations will help you remember them better than just
trying to memorize a list.
You
must study regularly. In a physics course, many topics are based on
preceding ones. Students who study regularly have the added advantage
of being able to
reinforce
and enlarge on what they already know while tackling something new.
The
study of physics requires a high degree of concentration. Solutions to
physics problems must be carried out carefully and in a precise, orderly
manner. Be sure to draw a sketch of the problem in order to clarify what is
being asked.
If
an error is made in a mathematical expression, it may be carried over to the
following parts of the problem. Solve your problems in pencil, neatly and
methodically. At every step of the analysis, be sure that you know your
reason for taking the step. Write your answers with the appropriate units.
PREPARING
FOR THE AP PHYSICS EXAM
Preparation
for an exam is normally a cooperative venture between students and
teachers, you should assume total responsibility for studying and learning
the material presented in the course.
Preparation
for an AP Exam through independent study is also possible. If you exercise
this option, the most important ingredient for success is strong
self-motivation, although it would be extremely useful to have access to a
teacher or tutor who can answer your questions and help you if you get
stuck.
The
AP Physics examinations are given in May. To provide the most information
about differences in students' achievement in physics, the examinations
are designed so that students earn average scores of about 50% of the
maximum possible score; this applies to both the multiple-choice section
and the free-response section. Therefore, you may find AP Examinations
more difficult than most classroom tests. However, it is possible for
students who have studied most but not all of the topics in the outline to
obtain acceptable test scores.
Most
AP students are accustomed to taking tests, both those prepared and graded
by their teachers and standardized exams. Virtually everyone knows that
regular study plus
reviews
of major elements in the course constitute the best preparation for tests.
Effective study for examinations will vary somewhat among students. For
example, many students find it helpful to study in a group with other
students, while for others, group preparation may not work well.
Some students can "cram" for a test, memorizing large amounts of
material in a brief period of time just before the test. For others,
cramming causes cognitive overload and exam-day confusion.
If
you want to master the skills and knowledge in your AP course, remember
that material that is reviewed periodically and skills that are reinforced
by practice are far more likely to remain with you than are those that are
hastily acquired and partially digested over a brief interval of time.
TEST-TAKING
STRATEGIES
It's
natural to be anxious when you are about to do something on which others
will judge your performance. The greatest anxiety moderator for most
people is knowledge; the more you know in advance about a course or an
exam, the better you can moderate your fears. Knowing about an exam
means understanding what kinds of questions you will be asked, how the
exam will be graded, how much time you'll have to respond, and so on.
Knowing that you are prepared in terms of the exam's content is probably
the most calming knowledge of all. Consistent study and review
throughout the course is a powerful reliever of excessive tension both
for daily classroom learning and for tests.
Directions
Be
aware that not paying enough attention to directions on tests can
adversely affect your grade. On the AP Exams, phrases in the
multiple-choice sections like "All the following are . . .
EXCEPT" or "Which of the following does NOT . . ."
contain critical words. If you don't pay attention to them, you will not
respond correctly to the questions.
There
are also special directions in parts of the free-response questions. For
example, there may be directions that specify for you to explain what
principles to use in deriving an expression or directions that ask you
to express an answer using specific variables.
Time
Limits
Make
a quick estimate of the amount of time the various questions or sections
of a test will require, stay aware of the time available throughout the
test, and concentrate on questions they can respond to best. Move on to
the next question if you can't figure out the answer to the one you are
working on.
In
the free-response questions, the number of points for the question is
specified after the question number. The number of points indicate the
weighting of the questions in the grading and are approximately equal to
the time that should be spent answering them for those who want to pace
themselves to finish in the given time limit.
Use
all the time available to complete the exam. If you finish the exam with
time to spare, go back to questions you skipped or answers that you can
supplement. Check the directions again to be sure you've responded
properly.
SUGGESTIONS
FOR THE MULTIPLE-CHOICE SECTION
Answer
Sheets
One
of the common mistakes while filling the answers of the multiple-choice
section is getting responses out of sequence; for instance, marking an
answer for question 5 when the answer was intended for question 6. This
can happen easily when you skip a question, put a mark in your test book
(not on your answer sheet) when you do this.
Frequently
check to be sure that the number of the question on your answer sheet
corresponds to the number of the question in your exam booklet.
Educated
Guessing
For
questions with five answer choices, one-fourth of a point is subtracted
for each wrong answer. This means that for answer sheets that are marked
completely at random, the average score would be expected to be zero.
Therefore, if you know absolutely nothing that helps you eliminate even
one of the multiple-choice options, you probably won't come out ahead by
guessing at an answer. But if you are fairly sure that even one of the
options is wrong, it may be worthwhile to answer the question. Of
course, if you can eliminate two or three options as probably incorrect,
your chances of gaining credit become even greater.
Eliminating
Incorrect Responses
Multiple-choice
questions are often very short problems with a choice of answers that
require a short calculation or derivation. However, you can use the
following tips to determine the answer more quickly or to eliminate
choices that are incorrect:
 *
In
some questions with numerical answers, the choices may differ by several
orders of magnitude so that the questions can be answered by estimation
rather than by exact calculation. You are encouraged to develop your
skills in making order-of-magnitude calculations to estimate such
answers more rapidly.*
Recognizing that some choices are physically unreasonable or unlikely is
often a good way to narrow the possibilities for the correct answer. For
example, if you are asked to calculate the time it takes for a ball to
fall from the top of a house, you could immediately eliminate answers of
0.01 second or 100 seconds, since they are outside the range of
physically likely possibilities.*
Some questions may ask you to derive an expression in symbolic form
rather than to calculate a numerical value. If you have trouble
determining the correct expression, you might try checking the units of
each choice. Those that do not have the units expected of the answer can
be eliminated. For example, if you are to determine an expression for a
distance, then an answer such as 2v/t, where v is speed and t is
time, would have the units of distance divided by time squared, and
would therefore be dimensionally incorrect.*
For questions that give expressions in algebraic form, you might also
look at limiting cases; that is, at what would happen to the expressions
if one of the variables were very large or very small. If an expression
predicts a result that could not be reasonably expected or that is
physically impossible, then that choice can be eliminated as the correct
answer. For example, the expression 6 + 2t could not be correct
for the speed of a ball released from rest at time t equal to
zero, since it does not go to zero as t goes to zero.
SUGGESTIONS
FOR THE FREE-RESPONSE SECTION
Before
beginning to solve the free-response questions consider reading all the
questions to determine which ones you feel best prepared to answer. Then
you can solve the questions in the order that will allow you to
perform your best.
You
should show your work for each part of a question in the space provided
after that part, and if you need more space you should clearly indicate
where you are continuing your work. You will NOT receive credit if the
grader cannot tell which part of the question you are answering.
Show
all your work. Partial credit is given for partial solutions to
problems. If you do not show your work, you may receive full credit for
an answer if it is correct, but you take a big risk because credit is
often based not just on the presence of the right answer but
on the correct use of appropriate steps leading to the
right answer. If the answer is not correct, you are not likely to
receive credit for correct thinking if the person scoring your
examination does not see evidence of this process on paper. If you do
work that you think is incorrect, you should simply put an "X"
through it, instead of spending time erasing it completely. Crossed-out
work will not be graded, and credit may be lost for incorrect work that
is not crossed out.
Organize
your answers as clearly and neatly as possible. Credit for your answers
depends on your demonstrating that you know which physical principles
can be applied in solving a particular problem, and an organized answer
in the appropriate answer space will better allow the grader to
determine whether you have demonstrated such knowledge. Also, show the
steps in your solution. If the grader cannot easily follow
your reasoning, you are less likely to receive credit
for it.
The
free-response questions on an AP Physics examination are usually divided
into parts such as (a), (b), (c), and (d), with each part calling for a
different response. Credit for each part is awarded independently, so
you should attempt to solve each part. For example, you may receive no
credit for your answer to part (a), but still receive full credit for
parts (b), (c), or (d). If the answer to a later part of a question
depends on the answer to an earlier part, you may still be able to
receive full credit for the later part, even if that earlier answer is
wrong. The grade will depend on your method of approach to the later
part and on the consistency of your answer with that of the earlier
part.
You
will sometimes be asked to justify your answer to a free-response
question. This indicates that the person scoring your answer is looking
for some analysis that will show how you derived your answer and prove
that your answer must be correct.
It
is not necessary to simplify all numerical expressions or carry out all
numerical calculations. Pay attention to units for quantities that have
them. Keeping track of units as you do calculations can help you make
sure that your answers are expressed in terms of the proper units. You
can lose points if the units are wrong or are missing from your answers.
Do
NOT write down a bunch of equations with the hope that the correct one
will be among them so you can get some partial credit. With the equation
sheets available, this approach is not likely to reward you with partial
credit, and you might lose points for giving extraneous or incorrect
information.
FORMAT
OF THE EXAMINATIONS
The
Physics B examination is three hours long and is divided equally in time
between a 70-question multiple-choice section and a free-response
section.
The
two sections are weighted equally, and a single grade is reported for
the B exam.
The
free-response section will normally contain six to seven questions.
Typical examples of its format are six questions, each taking about 15
minutes, or four questions of about 15 minutes each and three shorter
questions of about 10 minutes each.
Content
of the Examinations:
The
percentages of each exam that are devoted to each major category are:
Newtonian
Mechanics (35%)
Fluid
Mechanics and Thermal Physics (15%)
Electricity
and Magnetism (25%)
Waves
and Optics (15%)
Atomic
and Nuclear Physics (10%)
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