XPINO SCHOLARS
LESSON PLAN
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WEEK : 1
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TERM : 1
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SESSION : 2017/2018
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SUBJECT: BASIC
TECHNOLOGY
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TOPIC:
MECHANICAL TRANSMISSION SYSTEM: FRICTION, DEFINITION AND CAUSES, LAWS OF
FRICTION
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CLASS: JS3
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DATE: 18/09/17 – 22/09/17
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LESSON PERIOD: 1 – 2
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Learning Objectives: At the end of the lesson, the
students should be able to:
describe
friction;
explain what
occurs when two objects rub against each other;
state the
frictional difference between tougher surfaces and smoother surfaces;
outline the three
main causes of friction;
define surface
roughness;
Study Questions:
What is friction?
What occurs when
two objects rub against each other?
What is the
frictional difference between tougher surfaces and smoother surfaces?
What are the
three main causes of friction?
What is surface
roughness?
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Key words:
Friction
Surfaces
Roughness
Laws of
friction
Lubrication
Lubricants
lubricate
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Instructional materials:
Lubricants,
different metal or wood surfaces, student’s palms, rags, etc.
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Previous learning:
The
students can describe the result of rubbing two palms together at a high
speed.
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Learning Activities in steps:
Step 1
– Lesson Introduction. Give the students
the term scheme of work.
Step 2
– Teacher states learning objectives – including study questions. Guide the
students to define ‘friction’. Show the students different metal and wood
surfaces, with palms.
When one object rubs and grates
another, it causes friction.
Friction can
be defined as a force that resists the relative motion or tendency to such
motion of two bodies in contact.
When a solid material slides over
another solid surface, there is always resistance to motion. This resistance
is what the scientists refer to as Friction.
Step 3
– The Teacher guides the students in differentiating tougher surfaces from
smoother surfaces.
·
The tougher the
surfaces rubbing against each other, the more the friction.
·
The smoother the
surfaces rubbing against each other, the less the friction
Step 4
– Class Discussion on Causes of
Friction
Causes of
Friction
The causes of the
resistive force of friction are molecular adhesion, surface roughness, and
the plowing effect.
Adhesion is
the molecular force resulting when two materials are brought into close
contact with each other. Trying to slide objects against each other requires
breaking these adhesive bonds. For years, scientists thought that friction
was caused by surface roughness, but recent studies have shown that it is
actually a result of adhesive forces between the materials.
Surface roughness
is a factor when the materials are rough enough to cause serious abrasion.
This is called the sandpaper effect.
When one or more of
the materials is relatively soft, much of the resistance to movement is
caused by deformations of the objects or by a plowing effect.
Step 5
– Give the students exercises
Step 6
- Teacher summarizes and evaluates lesson.
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Learning Timing:
10
minutes
20
minutes
10
minutes
15
minutes
15
minutes
10
minutes
|
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Differentiation:
Level
1: students that should be able to achieve 80 – 100 %
Level
2: students that should be able to
achieve 60 – 79 %
Level
3: students that should be able to
achieve 50 – 59 %.
|
Resources:
Introductory Technology for
Schools and Colleges. Book 1. Evans, pg. 3 – 7
Fundamental in Basic Technology
for Jnr. Sec. Schools Basic 7. Idowu O.C.J. pg. 1 – 5
Sets of Mathematical Instrument
Sets Square and Drawing
Instruments
|
|
Evaluation:
What is
friction?
What
occurs when two objects rub against each other?
What is
the frictional difference between tougher surfaces and smoother surfaces?
What are
the three main causes of friction?
What is surface
roughness?
|
Key Skills:
Listening
skill
Critical
thinking skill
Researching
skill
Problem
solving skill
|
|
Assignment:
What are
the five laws of friction?
What is a
lubricant?
What
does it mean to lubricate?
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||
Name
of Subject Teacher: _______________
Signature:
______________________________
Head of
Department: _____________________
Signature:
______________________________
XPINO SCHOLARS
LESSON PLAN
|
|||||
WEEK : 1
|
TERM : 1
|
SESSION : 2017/2018
|
|||
SUBJECT: BASIC
TECHNOLOGY
|
TOPIC:
MECHANICAL TRANSMISSION SYSTEM: FRICTION, DEFINITION AND CAUSES, LAWS OF
FRICTION
|
||||
CLASS: JS3
|
DATE: 18/09/17 – 22/09/17
|
LESSON PERIOD: 3
|
|||
Learning Objectives: At the end of the lesson, the
students should be able to:
list the
five laws of friction;
identify lubricants;
explain
what it means to lubricate to lubricate an object.
Study
Questions:
What are
the five laws of friction?
What is a
lubricant?
What does
it mean to lubricate?
|
Key words:
Laws of
friction
Lubrication
Lubricants
lubricate
|
||||
Instructional materials:
Lubricants,
different metal or wood surfaces, student’s palms, rags, etc.
|
|||||
Previous learning:
The
students can describe the result of rubbing two palms together at a high
speed.
|
|||||
Learning
Activities in steps:
Step 1 –
Revision of last lesson.
Step 2 – The
Teacher guides the students in a class discussion on Laws of Friction.
Laws of friction
There are five laws of friction. These are:
1.
When an object is moving, the
friction is proportional and perpendicular to the normal force (N).
2.
Friction is independent of
the area of contact so long as there is an area of contact.
3.
The coefficient of static
friction is slightly greater than the coefficient of kinetic friction.
4.
Within rather large limits,
kinetic friction is independent of velocity.
5.
Friction depends upon the
nature of the surfaces in contact.
Step 3 – Class
activity:
1.
How can friction be created?
2.
How can friction be reduced?
3.
What are the advantages of
friction?
4.
What are the disadvantages of
friction?
Step 4 –
Class Discussion on Lubricants.
Show the students the available examples of lubrications.
A lubricant is an oily substance that makes
surfaces smooth and slippery, thereby reducing heat, wear, friction and
vibration caused when two or more surfaces rub together.
Lubrication reduces friction. To lubricate
means to apply oil in order to reduce friction, heat, and wear and tear.
Step 5 – Give
the students exercises
Step 6 - Teacher
summarizes and evaluates lesson.
|
Learning Timing:
5
minutes
10
minutes
5
minutes
5
minutes
10
minutes
10
minutes
|
||||
Differentiation:
Level
1: students that should be able to achieve 80 – 100 %
Level
2: students that should be able to
achieve 60 – 79 %
Level
3: students that should be able to
achieve 50 – 59 %.
|
Resources:
Introductory Technology for
Schools and Colleges. Book 1. Evans, pg. 3 – 7
Fundamental in Basic Technology
for Jnr. Sec. Schools Basic 7. Idowu O.C.J. pg. 1 – 5
Sets of Mathematical Instrument
Sets Square and Drawing
Instruments
|
|
Evaluation:
What is
friction?
What
occurs when two objects rub against each other?
What is
the frictional difference between tougher surfaces and smoother surfaces?
What are
the three main causes of friction?
What is
surface roughness?
|
Key Skills:
Listening
skill
Critical
thinking skill
Researching
skill
Problem
solving skill
|
|
Assignment:
What is
adhesion, in relation to friction?
Explain
plowing effect.
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||
Name
of Subject Teacher: _______________
Signature:
______________________________
Head of
Department: _____________________
Signature:
______________________________
Xpino SCHOLARS is a work tool for teachers and students, but especially for Secondary School Students. Comprehensive lesson notes, with exercises. Past questions in specific subjects for revision and research.
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