Second Term Lesson Note for Week Three
Class : SSS 1
Subject : Physics
Topic : Expansion of Solids
Duration : 40 Minutes
Period : Single Period
Reference Book :
- Lagos State Unified schemes of work for Senior Secondary School (SSS 1 – 3)
- New School Physics for Senior Secondary Schools.
- Online Resources
Instructional Material : Chart showing expansion of Solids
Learning Objectives : By the end of the lesson learners will be able to
i. Define Expansion
ii. Identify the effects of Expansion
iii. Mention some application of expansion.
CONTENT
Effect and Application of Thermal Expansion of Solid
Advantages and Disadvantages of Thermal Expansion of Solid
Effect and Application of Thermal Expansion of Solid
When hot water is poured in a glass tumbler, it might crack due to the uneven expansion of the inner wall of the tumbler.
The cracking noise of zinc roof during the day and night.
Thermal expansion of solid is used in the construction of bridges in which one side is fixed and the other is placed on rollers to allow for expansion.
The stopper of a bottle can be removed due to the expansion of the glass.
In the construction of concrete pavement, little spaces are left within the concrete to allow for expansion.
Gaps are left in the construction of railway tracks to give room for expansion.
Bimetallic stripes are use in thermostat for controlling or regulating the flow of electric current.
Advantages and Disadvantages of Thermal Expansion of Solid
Advantages
- Fire alarm e.g. electric bell
- The fittings of wheels in rims
- Bimetallic thermometer
- Red hot rivet in ship building
- Bimetallic stripes used in thermometer e.g. electric cooker etc
Disadvantages
- Cracking of drinking glass when hot liquid poured inside
- If the balance wheel of a watch expands the time will be fast and if the balance wheel of a watch contrasts the time will be slow
- Expansion of metal of concrete bridges which can lead to eventual after a long period Sagging of overhead wire due to contraction in winter season
- Expansion of railway tracks thereby forming distant railway tracks.
- Bursting of water metal pipes.
Presentation Steps :
Step 1 : Revision of the previous lesson with the learners by asking questions orally.
Step 2 : Introduces the new topic by explaining expansion
Step 3 : Identify the effects of expansion and it application area.
Step 4 : State advantages and disadvantages of expansion on an object.
EVALUATION :
1. Gaps are left in the construction of railway tracks to give room for .
A. contraction B. evaporation C. expansion D. vaporization
2. When hot water is poured in a glass tumbler, it might crack due to the of the inner walls of the tumbler A. even expansion B. uneven expansion C. uneven contraction D. even contraction
3. The stopper of a bottle can be removed due to the of the glass
A. contraction B. expansion C. evaporation D. none of the above
4. The following are advantages of thermal expansion of solids except A. bimetallic thermometer B. fire alarm C. sagging of overhead wire D. fitting of wheels in rims
5. If heat is removed from solids they ______________ A. contract B. evaporate C. expand D. none of the above
THEORY
1. Mention four effects of thermal expansion of solid.
2. Mention four the advantages and disadvantages of thermal expansion of solid.
3. Mention four effect of thermal expansion of solid.
4. Mention four the advantages and disadvantages of thermal expansion of solid.
Conclusion : At the end of the lesson learners were able to answer the questions correctly. The Teacher marks their notebooks and make necessary corrections.
Assignment :
Read : Types of expansion of solid ( New School Physics page 37 – 42.