Friday, 19 September 2014
Name of school : Standard :
VIII
Name of teacher : Lakshmi L Date :
Subject : Physics Duration
:
Unit : force
Subunit : Contact force
|
1.
Name of concept : Contact force
2.
Definition of the concept : The force applied on an object by
contact is called
contact force
3.
Essential attributes : Magnitude of force, nature of the
surface
4.
Non-essential attributes : temperature, color of the object,
position of the
Object.
5. Preparation of exemplars
Positive exemplars Negative
exemplars
A child pulls a
table A
man stand with a load on his head
A batsman hits a
ball falling
of mango
A man pulling a
cart Magnet
attracts nail
A boy pushes the
car Attraction
of earth on moon
Hammering the
nail the
nucleus of an atom attracts electrons
6. Instructional effects
a) Competence for close, meaningful
observation of examples and non-examples leading to attribute analysis.
b) Ability to identify the essential
attributes of the number of the category.
c) Competency in generating meaningful
hypothesis regarding the new category.
d) Practice of testing hypothesis formed
in the light of new examples.
e) Skill of categorizing the items
observed on the basis of essential attributes.
f) Skill to define the category formed
in terms of essential attributes.
Ability
to generate new examples independently and to list the acceptability
7.
Nurturant effects
a) Acquires sensitivity to logical
reasoning
b) Becoming tolerant to ambiguity.
c) Developing positive attributes
towards alternative perspectives.
SYNTAX
Phase 1
Presentation of data and concept identification
|
||
T:
S:
S:
T:
S:
T:
S:
T:
S:
T:
S:
T:
S:
T:
S:
T:
S:
T:
|
Dear
students we are going to play a game. I have a concept in my mind. I will provide you some positive examples
for the concept in my mind and some negative examples which do not bear the
characteristics of the concept. All the yes example have some attributes in
common. By comparing the examples you have to identify the concept in my
mind, its characteristics and suggest some more examples. Moreover based on
the attributes you have to define the concept.
Here
is the pair of positive and negative examples.
A child pulls a table (+ve)
A child standing with a load on his head.
(-ve)
Something
that a child can do
Something
related to motion
Now
listen, there is your second set of examples.
A batsman hit the ball (+ve)
A man standing with a load (-ve)
Something
related to motion of an object.
If so check the next
set of examples
A man dragging a bag (+ve).
Falling of mango from tree (-ve).
Something related to
force.
Let us see the next
set of examples
A man pulling the cart (+ve).
A magnets attracts a nail (-ve).
In all the positive
examples force is applied by contact.
You are absolutely
correct. Can you name the concept?
No teacher
All right, I will
tell you. This is known as contact force.
Can you list the
attributes of contact force?
Magnitude of the
force applied.
Very good.
The force applied on
the object by contact is called contact force.
In the above
mentioned positive position of the object is a non-essential attribute. Can
you suggest some other non-essential attributes?
Color of the object.
Anything more?
Quantity of the
object.
Absolutely right.
|
The teacher presents the first pair of
labeled examples
Hypothesis 1
Hypothesis 2
The teacher presents the second set of
labelled examples.
Hypothesis 1 rejected
Hypothesis 2 persist
Teacher presents the third set of
examples.
Hypothesis 3
The teacher presents the fourth pair
of labelled examples.
Hypothesis four is formed.
Teacher name the concept.
Students list the essential
attributes.
The teacher states the concept.
Students list the non-essential
attributes.
|
Phase
2
Testing
the attainment of concept
|
||
T:
S:
T:
S:
T:
S:
T:
S:
|
Now I am going to check your knowledge
about contact force. I will give you a set of examples from which you should
identify the YES examples and NO examples.
Pushing the wall and
Earth attracts moon
Pushing the wall – yes
Attraction of earth on moon – no
Now listen the next examples.
Hammering a nail on a wall.
Revolution of planets around sun
Hammering nail on a wall – yes
Revolution of planets around sun – no
Now listen the next examples
Stretching the rubber band.
The nucleus of an atom attracts electrons.
Stretching the rubber band – yes
The nucleus of an atom attracts
electrons – no
Very good. Can you define contact
force?
The force applied on a body by contact
is called contact force.
|
Students label the unlabeled examples
Students label the unlabeled examples
Students label the unlabeled examples
Students state the concept.
|
Phase
3
Analysis
of thinking strategy
|
||
T:
S:
T:
S:
T:
S:
|
Can you explain how
did you reach at our conclusion?
Teacher your firs
positive examples of child pulls a table and a man carrying a load make as to
think that the concept may be something related to motion and also which can
be done by a child. But when you provide the next positive example that
hypothesis was rejected.
What about the next
examples?
When you told about
falling of a mango from a tree as negative example we thought that the
concept was related to something like force and also involves motion.
Then how will you
reached at the final conclusion?
We analyzed the
positive and negative examples again and again. On comparing, we come to
identify in all the positive examples force is applied by contact. Thus we
arrived at the concept of contact force.
|
Students describes the thought.
|
SCIENCE
LABORATORY
The laboratory is the
centre to science education. It is in the laboratory that students learn to
handle apparatus, think independently and to draw conclusions on the basis of
experiments and observation. Laboratory work is an essential component of
science education. Scientific theories
and practical work are two sides of a coin. These two aspects of science
education should complement and supplement each other. Without experiments
students cannot experience the reality of science. Practical works provides an
activity which can be profitable and emotionally satisfying. The development of
powers of observation, measurement and drawing inference are all dependent on
laboratory work. Laboratory work helps to realise the process oriented
objectives of science education.
NEED AND
SIGNIFICANCE OF LABORATORY WORK IN SCIENCE EDUCATION
1. The students can
experience the reality of life.
2. Practical works provide an
activity which can be profitable and emotionally satisfying.
3. Helps in development of
powers of observation, measurement and drawing inference etc. in learners.
4. Laboratory work helps to
realise the process orient objective of science laboratory.
5. Making abstract science
understanding concrete.
6. Developments of scientific
principle and concepts.
7. Development of scientific
skills, attitudes, interests and appreciation.
8. Training in scientific
method.
9. Awakening the maintenance of
curiosity in the environment.
ADMINISTRATION
OF LABORATORY WORK
In order to make the
practical work most effective, the teacher should always keep in mind the
different aspects of laboratory work.
1. Organising and conducting
practical work.
Ø There should be
coordination of theoretical and practical work.
Ø Experiments should be
neither too difficult nor too easy.
Ø The purpose of experiment
should be made clear to pupils.
Ø A faithful record of the
experiments should be maintained by the pupils.
Ø Pupils work should be
keenly observed by the teacher.
Ø Experiments should be
graded according to age, intelligence, etc.
2. Students should make to
form appropriate groups.
3. Preparation is required
for individual and group work.
4. Laboratory rules and
discipline should be laid down.
5. Instructions to pupils are
to be specific and clear.
6. Pupil’s records and
observation book are to be properly maintained.
FEATURES OF
A GOOD SCINCE LABORATORY
A good science laboratory
should satisfy most of the following characteristics.
1. It must be spacious-
Linear bench space, storage space, permanent equipment space, demonstration
space etc.
2. It must quit conductive
for hard work.
3. Its plan must provide
elements of flexibility for effective teacher demonstration as well as for
individual and small group work.
4. It must provide certain
facilities for objectification.
5. It must permit enough
teacher supervision of the pupil’s work.
6. It must have water, gas
and electric points wherever they are needed.
7. It must have ample storage
facilities for equipment.
8. It must have an emergency exit if it is not
situated on the ground floor.
SELECTION
AND PURCHASE OF APPARATUS AND CHEMICALS
While making a list of requirements
the teacher should consider the following factors.
a. Types of apparatus
required.
b. Quantity of each item.
c. Choice of suppliers.
d. Finance
e. The number of subjects
taught.
f.
The number of students and their level.
g. The capacity of the
laboratory.
h. The knowledge and ability
of the teacher.
PUECHASE OF
APPARATUS AND CHEMICALS
After a list of selected
items has been prepared, its copy is sent to three or four firms and quotations
are obtained. One receipt of quotation, order should be placed to the firm
which supplies the better equipment at cheaper rate. Local dealers should be
preferred. If possible the teacher should go personally to the firm and get the
things packed in his presence. On receiving the goods, the teacher should check
with the list before signing their receipt. Any broken or damage items,
incorrect quantities or wrong items supplied must be immediately informed to
the dealer. The items should be entered in the school register on the same day.
REGISTERS
MAINTAINED IN THE LABORATORY
Permanent
stock register
In this register articles
of metal, wood or permanent nature which are not liable to broken or consumed
are to be entered. E.g. test tube rack, wooden stands, magnets, microscope,
spectrometer etc.
Stock register of breakables
Articles of
glassware like flask, beaker, funnel which are liable to broken are included in
the register
Stock
register of consumables
Chemicals and other fluids
which are liable to be consumed are entered in third register.
Order
register
This includes a record of
orders send for purchase of apparatus and chemicals to different firms.
Requirement
register
In the requirement
register, the teacher should not down the requirements which he remembers at
the time and which he feels necessary during the experiment.
LABORATORY
RULES AND DISCIPLINES
Laboratory safety is
positive understanding which the science teacher is expected to take up at the
time of engaging any activity in the laboratory, in presence of his students.
The following are the some suggestions for the maintenance of discipline in the
laboratory.
1. No pupil should allowed to
enter the laboratory in the absence of the teacher.
2. Pupil should perform only
those experiments assigned by the teacher.
3. Every students should have
a place assigned to him for his experiment.
4. Equipment/chemical should
be used until proper instructions are received from the teacher.
5. Specimens, solid waste,
broken glass, burnt up match sticks and other laboratory wastes should be
deposited in waste boxes.
6. Reagent bottles should be
returned to the shelf immediately after use and these should not be misplaced.
7. Any breakage of apparatus
or accidents or injury must be reported to the teacher.
8. Playing with the apparatus
should be prohibited.
9. The apparatus should be
disconnected, washed if necessary and replaced in their proper places.
10. Consider the safety of
fellow students. A scientific atmosphere should be kept up in the laboratory
ACCIDENTS
AND FIRST AIDS IN THE LABORATORY
The science teachers have a legal and moral responsibility to see that
the pupils are safe from the dangers of the laboratory. Pupils must be aware of
the hazards involved in any experiments they do. Pupils must be made to
understand the laboratory rules and follow them.
The purpose
of the first aid is to make patient secure and comfortable and to prevent
deterioration in his condition, until professional medical assistance is
available. The strategies of first aid-diagnosis, treatment and transport
1. FIRE
a) If a person’s cloth catch fire, to be wrapped
tightly in a fire proof blanket.
b) If some inflammable
substance get ignited in a beaker the fire can be extinguished and prevent from spreading by pressing
a sheet of asbestos over the mouth of the vessel.
c) Small fire due to oil,
phosphorous, sodium etc. can often be put by smothering them with large quantity of sand.
d) If the fire is due to gas
or electricity, the source of supply or the main connection should be cut off.
2. BURNS
Burn is caused by dry heat such as
hot iron, hot glass rode, fire, by some acid or alkali,phosphorous or sodium or
potassium.
a) Burn from fire
Burnol paste is smoothly applied and allowed to remain on
the burnt part. If necessary a loose bandage to be tied.
b) Acid burns
Acid burns must be immediately washed with large quantity
of water and then sodium bicarbonate solution.
c) Alkali burns
Alkali burns must be washed with 1% solution of acetic
acid or lemon juice.
d) Phosphorous burns
Phosphorous burns must be immersed in water and all the
traces of the substance washed away. The part should be treated with dil. AgNO3.
3. EYE BURNS
Acid in eye: the eye
should be open and closed under water. It should be then washed with water or
1% solution of sodium bicarbonate.
Alkali in eye: The eye
should be thoroughly rinsed with water and then with 1% solution of boric acid.
Solid in eye: The eyelid
may be turned back gently over a match stick. Any foreign matter may be removed
with fine camel brush dipped in glycerine.
4. POISONING
a) For corrosive substances
The patient should give white egg or milk, and rice water
or barley water. He should not be encouraged to vomit or should not give any
purgative.in the case of acids much water followed by lime water or milk. In
case of alkalies much water followed by 1% acetic acid or lemon juice.
b) For non-corrosive poisons
A spoonful of table salt
or a tea spoon full of mustard oil in a tumbler of water should be should be
given. This will encourage vomiting. The white of egg or rice water may be also
given.
5. INHALATION OF GASES
In the case of gas poisoning, the patient should at once
be taken into the fresh air and his clothes should be loosen.
By chlorine or Br2 : Inhale
ammonia or alcohol vapour.
By nitrous fumes : Inhale
open fresh air.
By chloroform : Inhale
plenty of fresh air.
6. CUTS
When there is a major cut
n any part of the body and some artery or vein is injured, it is essential to
stop the bleeding. In order to stop bleeding, it is necessary to understand
whether a vein or artery has been cut. If it is continues blood flow, then the
vein has been injured. For that in direct pressure should be applied by tying a
narrow bandage on the distal of the wound but care should be taken the pressure
applied should be taken the pressure should only collapse the vein and not the
artery. If the blood spurts then artery has been cut, pressure on the proximal
side of the wound or in extreme cases the use of tourniquet may be necessary to
control it.
Subscribe to:
Posts (Atom)