Lesson Notes By Weeks and Term v4 - JHS 3
ENERGY
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ENERGY
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Subject: Science
Class: JHS 3
Term: 2nd Term
Week: 8
Grade code: B9.4.1.2.3
Strand code: 4
Sub-strand code: 1
Content standard code: B9.4.1.2
Indicator code: B9.4.1.2.3
Theme: FORCES AND ENERGY
Subtheme: ENERGY
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In our daily life in Ghana, we see shadows everywhere—under a mango tree at midday, behind a classroom building in the afternoon, or during a power outage when we use a torchlight. Shadows are not just “dark patches”; they form in specific ways depending on the light energy source and the object blocking it. Understanding umbra and penumbra helps learners explain real events like solar and lunar eclipses, why shadows change size during the day, and why a torchlight can produce a “fuzzy” shadow.
2.1 Energy Link (Why this is in “Energy”) Light is a form of energy that travels in straight lines (as rays) from a source. When light energy is blocked, some areas receive no light or less light, creating different parts of a shadow.
2.2 Key Definitions (a) Light source Anything that produces light energy, e.g. the Sun, candle flame, torchlight, phone flashlight, bulb.
(b) Opaque object An object that does not allow light to pass through it, e.g. a book, a stone, a wooden door.
(c) Shadow A dark region formed on a surface when an opaque object blocks light from reaching that surface.