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PHYSICS IS FUN,
EXCITING, SIMPLE Ian Cooper email: matlabvisulaphysics@gmail.com
A basic goal of science is to explain a wide range of phenomena in
terms of a small number of powerful, fundamental physical principles. Learning physics is like learning a
foreign language such as Chinese. Not only do you have to know the words and
meanings but how to put it all together to have successful communication. The language in physics is very specific and the meaning of words can
be different to when used in everyday speech. You will have to learn the
“restricted” meaning of words and how they relate to describing
our physical word, and the basis of describing our physical word is in the
use of models. A major goal for yourself is to be able to
give good scientific explanations in answering questions correctly. The following paragraphs highlight the criteria for good scientific
explanations, on which you will be assessed continually. You should repeatedly refer to the criteria, so that in your
examinations you will be able to give good scientific explanations in your
answers and maximize your marks. A good answer is not just a collection of words, equations and numbers.
Often in physics, a good answer to a question combines features of an essay
and a mathematical proof - it clearly and coherently communicates your
thinking about a question to someone else and it presents a logically valid
chain of reasoning based on established principles. Just as you can tell the difference between a good essay and a poor
one, or a good geometry proof and an inadequate one, you will need to learn
to distinguish between good and poor scientific explanations. Criteria For Good
Scientific Explanations Explanation based on fundamental physical principles including relevant equations and not just a description. A description tells what happened; an explanation tells why it happened, in terms of fundamental scientific principles.
Scientific words have very precise meanings and they must be used
precisely. Unlike everyday speech, where it is permissible to substitute many
different words for each other, there are very few synonyms in science. If
you use the wrong word, your statement may be meaningless or utterly
incorrect. Here are some important words that are frequently misused by
novice students: work, pressure, force, acceleration, velocity, amplitude,
charge, charged, field, induce, induction, ionize, ionization, neutralize, potential. For example, a force and charge are utterly different concepts; they
are connected conceptually by the fact that a charged object can exert a
force on another charged object. Here are some examples of meaningless statements from students' answers:
"The charge attracts to the positive dipole." and "The metal
block is induced by the touching of a positive charge." Explanations
of physical phenomena can be given as several precise steps (chain argument).
Diagrams Readable, relevant details, labels Scientists draw diagrams all the time. They use diagrams as a tool to
support and guide their own thinking, as well as a device for explaining
their ideas to others. Many students are reluctant to draw diagrams. As reasons for their
reluctance students say things like "I'm not good at drawing,"
"It takes too much time," "It's redundant, because I have to
explain everything in words and equations anyhow." A common thread in
these statements seems to be the perception that a diagram is a decoration,
not a tool. Many students have not yet learned to use diagrams in a way that
can guide their own reasoning and prevent many errors. Readability:
A diagram must be large enough to see and interpret easily. Do not draw
little teeny diagrams in the margin of your paper. Make the diagram big
enough that all the important information can be included in it, and can be
interpreted easily by a reader. A diagram should not be ornate. Use simple,
clean lines. Labels:
By labelling all distances, charges, and forces in a diagram, you
bring together in one place a great deal of information that is scattered
throughout the problem. Once it is recorded on your diagram you do not have
to search for it again. Labels help to prevent serious errors. Carefully
labelled diagrams significantly reduce the number of errors made in problem
solutions. Include
only relevant details: A cluttered diagram is hard to interpret.
For clarity, include only relevant information. For example, show only excess
charges, but do distinguish between charge on a surface and charge inside an
object. Do distinguish between free and bound charges - do not make your
drawings of polarized molecules in an insulator look the same as a drawing of
a polarized metal. These distinctions are important physical distinctions, so
diagrams must reflect them unambiguously. Often a good diagram can bear the major burden of explanation, with
little or no accompanying prose required to make the point. A useful diagram
is the centrepiece of a good explanation. Meaning of verbs account, account for state reasons for, report on, give an account of, narrate a
series of events or transactions analyse identify
components and the relationships among
them, draw out and relate implications apply
use, utilize, employ in a
particular situation appreciate make a judgment about the value
of
something assess make a judgment of value, quality, outcomes, results or
size calculate determine from given facts, figures or information clarify make clear or plain. classify arrange
into classes, groups or categories compare show
how things are similar and different construct make, build, put together items
or arguments contrast show
how things are different or opposite critically analyse add a degree or level of accuracy, depth, knowledge,
understanding, logic, questioning, reflection and quality to an analysis or
evaluation deduce draw
conclusions define state
the meaning of and identify essential qualities demonstrate show
by example describe provide
characteristics and features discuss identify
issues and provide points for and against distinguish recognize
or note/indicate as being distinct or different from, note difference between
things evaluate make
a judgment based on criteria examine inquire
into explain relate cause and effect,
make the relationship between things evident, provide why and/or how extract choose
relevant and/or appropriate details extrapolate infer
from what is known identify recognize and name interpret draw meaning from investigate plan, inquire into
and draw conclusions about justify support
an argument or conclusion outline sketch
in general terms; indicate the main features predict suggest
what may happen based on available information propose put
forward (a point of view, idea, argument, suggestion etc.) for consideration
or action recall present
remembered ideas, facts or experiences recommend provide
reasons in favour recount retell
a series of events summaries express
concisely the relevant details synthesize put
together various elements to make a whole |
