School Science Lessons
Physics - Resources for physics teaching
Updated: 2007-09-19
Please send comments to: J.Elfick@uq.edu.au
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Table of contents
1.0 Resources for physics
teaching and their application
1.1 The natural world
1.2 The social environment of students
1.3 The daily life of students
1.4 Physics experiments
1.5 Equipment and support systems
1.0 Resources for
physics
teaching and their application
The best resources for physics teaching are physics experiments that
have a clear aim and have been prepared in a physics laboratory
preparation
room. However, this is not enough for educating high school students.
Physics
becomes attractive and interesting to them only if their learning from
nature, their social environment and their firsthand experiences as
students
are combined with theoretical physics teaching. Only then can they
master
the methods of physics and understand the relationship between physics
and human society.
1.1 The natural world
1. Students have accumulated abundant experiences of the natural world
since childhood. These experiences and their understanding of the
mysteries
of the natural world produce a great impact on their learning interest
in the method and content of physics. You must give our attention to
how
to apply the experiences and understanding of students to physics
teaching.
Many interesting investigations may be based on careful observation of
the wind, rain, thunder, electricity, frost, snow, dew, and hail, and
lead
to further thinking. For example, the falling motion of rain, snow and
hail differ so that their shape, volume, speed and harm to plants
differ.
You may observe that the rainwater on the sunken part of a lotus leaf
and
dew remaining on the pine needle and grass blade can have different
shapes.
If you observe the substances attached to by frost and dew, you may
wonder
why they "prefer" to attach to branches and blades of grass and even
hair
but not the earth.
2. Of course you should be clear about the
basic questions, e.g.
whether
the lightning flash bolt is seen just when you hear the thunderclap.
However,
further thinking is more significant if students can study or find out
for themselves. For example, how do clouds become charged? Are there
clouds
with no charge in the sky? Do cyclones form like a vortex? Why does
rain
form like a screen but hail form in a line? Perhaps the physical
surroundings have wider usage to physics learning of students. Flowers,
grass, trees, woods, mountains, stones, earth, sand, mud, river and air
in the natural world are all resources for mastering physics knowledge
through observing and testing. They may make students feel the
profundity
of sciences. You may reach completely different conclusions if you
feel
the temperature of tree and rock by touching with a hand then measuring
in hot summer and cold winter. If you try to pull a dried little
tree out of the earth, you may be ashamed of your lack of strength! You
will find that their roots cannot grasp stones under ground. It may
help
students to know how friction and plants prevent water and soil from
moving.
In summer, forests or caves are always cooler than outside as if
independent
of the flowing hot air around them or outside. The temperature
difference
of sand in the morning and evening is different from that of pool
water.
By simple measurement of temperatures at these places, students may
more
vividly comprehend density, pressure, specific heat, convection and
climate.
Walk on the earth, sand and mud wearing different shoes and simulate a
short ski. Try to touch sand grains or pebbles in water according to
the
position and depth as seen from the bank. Encourage students to do such
experiments that you can accomplish with few tools or equipment. They
may
provide unexpected help for students to learn physics.
3. Many physics questions appear in the
natural world. When throwing
two pebbles with different weight simultaneously onto a river, one of
them
may bounce farther than the other. Spray produced by pebbles seems no
longer
transparent but white. Different sprays fly up with different heights
and
fall down at different positions. Smaller spray may fly up higher and
fall
down farther. Waves caused by pebbles falling into water spread as
concentric
circles and interference may also occur. The waves will spread farther
and the waves will not take away anything but leaves and twigs remain
floating
on the water. So many phenomena are helpful preparation for students to
learn and apply much physics knowledge such as kinematics, dynamics,
optics
and theory about fluctuations. While observing, you should
energetically
advocate the finding of questions and using applied learned knowledge.
For
example, consider a big tree growing slanting from the bank of a river.
Why does it not fall down? Is its centre of gravity still at the area
of
its root support?
4. Consider the animals around us in
nature. By carefully watching
a duck swimming in a river, you can find that the duck moves ahead just
by pulling water backwards and that duck feet have different shapes
when
the duck pull water backwards and when they return ahead. You relate
this
change in ducks' feet to the force acting on them and the structure of
their bones. By observing the eyes of a cat in the sunshine and dark,
you
can observe the effect of apertures. The call of frog, cricket and
rooster
can give us examples of vibration producing sound although you may not
hear
some vibrations, e.g. vibration of wings of bee, mosquito and dragonfly
as they fly. Sharp teeth and claws of carnivores and sharp beaks of
birds
can all exert great pressure. If you hold a cat standing then remove
your
hands, you will find that it puts out the sharp claws previously hidden
to try to increase pressure to seize your clothing or body. Observe a
squirrel
walking freely on thin branches. You can find that its beautiful and
thick
tail adjusts distribution of its body mass at any moment just like a
long
pole held in the hands of a player walking on a steel wire. By taking
note
of biological development you will again get more vivid examples for
teaching.
5. To sum up, when you go into the natural
world, material helpful
to physics teaching may be found everywhere if you observe, think and
experiment.
It is also the same in the sky or universe. Consider the moon for
example.
Physicists must spend some effort to deal with questions about the
moon;
questions about its change in shape, ascending and declining around the
earth, hiding briefly during lunar eclipse, reflecting sunshine but not
warm. Why does it not fall on the ground like an apple? These questions
arise only after daily observation. More embedded questions exist. For
example, they might have made an error of 1000 metres from the landing
spot, unacceptable in space science, if they launched a space ship to
the
moon using the standard metre rulers of the Paris Metrology Bureau as
the
length benchmark. They needed a new length benchmark. Nature provides a
great deal of interesting materials for physics teaching just as it
provides
boundless opportunities for research.
1.2 Social environment of students
1. In the natural world, many non-natural things around students may
become resources for physics teaching. Observation of people, meeting
in
a hut, a classroom, a showplace and a park arbour, may provide much
knowledge
on acoustics, heat stored in fuel, and optics, such as sound
reflection,
absorption and echo, air convection, quantities of heat discharged by
humans
and the environment temperature, sound insulation and humidity
protection,
diffuse reflection, illumination, disorder motion of particles of light
beams etc. Observe portrait pictures, photographed at the same
exposure,
in a room with a white wall and in another room decorated with dark
coloured
wallpaper. Then analyse their colour and contrast. You will learn much
practical physics knowledge. Vehicles, sails and aircraft in daily
life
may provide not only knowledge on kinematics and dynamics, such as
velocity
and acceleration of different motion, force and reaction, but also
practical
experience about falling, inertia, friction, momentum, change of
atmosphere
pressure and the eardrum, even to observe motion phenomena of
non-inertial
systems.
2. Besides the physics principles in
construction or equipment, there
is much knowledge of problems of daily life and application of physics,
e.g.
(a) Sailing boats, See 11.4.11:
Estimate
the load of a boat,
(b) Pollution from noise, noise effects thinking and learning, white
noise, See 34.4.1: Pollution from
noise,
(c) Personal safety, See 4.2.5:
Necessity
of seat belts in a car, problems of daily life and application of
physics
3. Unlike the natural environment, the
social environment can
transfer
to students much useful information about physics if you remind or
encourage
students to notice, to increase contact with the information resources,
and to keep alive their curiosity, desire to learn and the goal of
learning. Everything is available including effective information
resources,
such as beneficial books, magazines and broadcasts, especially
television
programmes distributing sciences and introducing developments in
science.
As an alternative approach to physics teaching besides the school
system,
you do not expect that it must provide systematic and high level of
scientific
knowledge. You do not mind this very much although you can understand
some
ideas better and more profoundly in school. Inspiring students'
interest
in sciences is important, develop their imagination, then put forward
questions.
Everything can be helpful to the growth of physics learning by
students.
Of course it may not only make teaching more interesting also widen the
perspective of students if teachers can bring their attention to get
information
from the resources then apply them correctly in physics teaching.
4. Environment protection is an important
question that has direct
bearing on the natural and social environment. Science and technology
have
successfully brought great advantages to humans but people ignore the
pollution
produced by these advantages. Thus any phenomenon, reason, prevention
and
cure causing physical pollution in the natural and social environment
should
become a resource for physics teaching, in the same way that all
physics
and its associated technology are a resource for physics teaching. A
basic
principle in physics teaching is to draw attention to physical
pollution
caused by lack of knowledge, e.g. the large amount of CFCs in the
ozonosphere,
exhaust gases produced by cars, greenhouse effect increasing year by
year; wastewater drained off from thermoelectric power plants and
temperature
increasing of water in river and lake caused by it, and destruction of
ecological balance in marine areas. These are examples of physical
pollution
of the natural environment. Examples of physical pollution of social
environment
that affect human health include electromagnetism pollution produced by
television transmitting towers and microwave communication,
radioactivity
pollution from nuclear industry, atomic power stations and radioactive
isotopes widely used in industry and agriculture and medical treatment,
and pollution coming from airports, workshops and construction sites.
In
fact the two kinds of physical pollution, of nature environment and
social,
cannot be separated completely because they have direct bearing on each
other, e.g. climate change in nature and destruction of ecological
balance
can directly affect human life. The increasing temperatures caused by
directional
reflection from exterior glass materials of buildings, not only
influences
residential life but also causes the "hot island effects" of large
architectural
complexes influencing climate change in local areas.
5. Pollution from light of buildings. You
should let students
understand
the phenomenon and reason for physical pollution and enhance their
awareness
of the need to protect the environment through making full use of
practical
examples in their social environment.
1.3 Experiences of students at first hand
1. For students, first hand experiences lead to the most direct
perceptions.
They can enable students to master easily physical knowledge and help
them
to understand the ideas and principles of physics. The experiences
of
students at first hand have been abundant, but they often overlook some
daily experiences. For example, motion always consumes energy. If you
feel
a glass sliding away, you always increase force to hold it. Hot things
will be cooler after being outside for some time. What you see through
a hole must be much wider than the hole. For the same size of a thing
the
farther away it is the more unclear it is. Any one of two faces of a
coin
may be upward after throwing the coin upward then letting it fall. So
recording
these experiences in time is not easy then apply them correctly.
However,
some experiences maybe cause students to misunderstand. For instance, a
bicycle will not move if no one pedals it, so students may think that
force
is the reason for motion. Also, people notice that horses pull vehicles
but not reverse order and people taking a beating always feel sorer
than
people beating. Such examples may cause students to doubt whether
really
equal and opposite forces exist. A grain always falls faster than a
piece
of paper. It may lead students to believe that the heavier an object
is,
the more rapid it falls down. You feel your hands are tired if you have
walked carrying a heavy load by hand. It may cause students to
misunderstand
that the hands have done work. Only by analysing these everyday
experiences
can you instruct students to know real science and its values, which is
very important for physics teaching.
2. An experience you have had may convey
different kinds of physics
knowledge, e.g. picking up a piece of beefsteak with a fork. The
experience
may be used to learn not only about pressure but also about levers. As
pointed out above, a practical phenomenon in the natural world often
includes
much different physics knowledge. The following examples may be more
complicated.
An experience may convey the same kind but different degrees of physics
knowledge. For instance, a passenger will fall over when a car
increases
speed or brakes suddenly. You may apply it not only to explain inertia
but
also to analyse the position of the centre of gravity. You can join
broken
light bulb filaments to work again. You may apply it to explain the
change
of resistance and current and power and to analyse temperature and
luminosity.
1.4 Physics experiments
1. Undoubtedly physics experiments are the most important resources
of physics teaching. Replacing the experiments prepared meticulously by
teachers by the experiments that students do in nature and at home is
impossible
in teaching efficiency and training of students' experiment skill and
accurate
measurement. Scientific conclusions of physics experiments entirely
depend
on accurate completion of physics experiments. Students' understanding
of many scientific methods also entirely depends on physics
experiments,
such as how to solve the questions of not exact measurements through
using
significant figures; how to deal with the questions of many factors
changing
simultaneously; how to analyse expected experimental results; how to
confirm
an experiment's reliability.
2. Demonstration experiments do not replace
practical experiments
carried out by students themselves in a laboratory. Both types of
experiments
should be well regarded in physics teaching. The more students do
themselves,
the more they get from the experience. It is very different from a
classroom
teaching, watching teachers' doing, listening to teachers' explanation
and following teachers' thinking. What students learn is entirely
different
if they complete a well organized experiment or they do everything
themselves
in an experiment, including the aim, the task, equipment. They learn
are
not only knowledge and skill but also thinking and operations of
challenge
and creation.
3. You should approve physics experiments
completed well with low
cost instruments or daily appliances as a qualitative experiment that
do
not require a high level of precision. It is not only for economic
reasons
but also because the experiments may be done anywhere out of a
laboratory,
at home or outside, to provide advantage for applying physics teaching
resources in nature or the social environment. However, you never do
anything
at the cost of decrease of experimental accuracy. For a physics
experiment,
no accuracy means no scientific status and thus no sense. For example,
if the frictional forces in the pulleys of low cost pulleys are greater
than the weights raised, this experiment is different from the simple
machine
studied in physics.
4. Physics experiments can be complicated
although
using few instruments or using low cost equipment. Using the body may
complicate
some experiments although such experiments may refer to broad content
and
give students direct experience, e.g. (a) When the inner surfaces of
fingertips
are pressed together both change in shape similarly; (b) See
experiment 8.2.6 Centre of gravity of man and woman. It is easier
for
the woman to pick up the chair because she has the lower centre of
gravity.
(c) If you hold the palm of your hand close to your cheek without
touching,
you can feel radiant heat. (d) By narrowing your eyes and looking
between
your closed fingers you may observe single slit diffraction.
1.5.0 Equipment and support systems
1.5.1.0 Equipment
1.5.1.1 Electronics
1.5.1.2 Timers
1.5.1.3 Position and Velocity Detectors
1.5.1.4 Sources of Sound
1.5.1.5 Sound Detectors
1.5.1.6 Circuits/components/instruments
1.5.1.7 Function Generators
1.5.1.8 Oscilloscopes
1.5.1.9 Advanced Instruments
1.5.1.10 Power Supplies
1.5.1.11 Light Sources
1.5.1.12 Light Paths Made Visible
1.5.1.13 Lasers
1.5.1.14 Microwave Apparatus
1.5.1.15 Computer Interface
1.5.2.0 Support Systems
1.5.2.1 Blackboard Tools
1.5.2.2 Audio
1.5.2.3 Slide Projectors
1.5.2.4 Film Projectors
1.5.2.5 Overhead Projectors
1.5.2.6 Video and Computer Projection
1.5.2.7 Photography
1.5.2.8 X y, Chart Recorders
1.5.2.9 Buildings
1.5.2.10 Museums
1.5.2.11 Resource Books
1.5.2.12 Unclassified Demonstrations
1.5.2.13 Philosophy
1.5.2.14 Films
1.5.2.15 Computer Programs
1.5.2.16 Mechanical
1.5.2.17 Motors
1.5.2.18 Pumps
1.5.2.19 Vacuum
1.5.2.20 Air Support
1.5.2.21 Ripple Tank