| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: define and use specific latent heat and distinguish between specific latent heat of fusion and specific latent heat of vaporisation |
Learning Objective/s:
- Define specific latent heat and write the equation \(Q = mL\).
- Distinguish between specific latent heat of fusion (\(L_f\)) and vaporisation (\(L_v\)) in terms of phase change and magnitude.
- Calculate the heat required for melting and boiling using given values.
- Interpret an energy‑vs‑temperature graph showing plateaus for fusion and vaporisation.
- Apply the concepts to solve real‑world problems such as melting ice or generating steam.
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Materials Needed:
- Projector or interactive whiteboard
- Slide deck with diagrams and equations
- Printed worksheet with practice problems
- Calculator for each student
- Ice, kettle, and a clear container for demonstration
- Thermometer (optional)
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Introduction:
Begin with a quick question: “What happens to temperature when ice melts?” Connect this to prior knowledge of heat transfer and set the success criteria – students will be able to define specific latent heat, differentiate \(L_f\) and \(L_v\), and use \(Q = mL\) in calculations.
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Lesson Structure:
- Do‑Now (5') – Short quiz on heat‑energy concepts to activate prior knowledge.
- Mini‑lecture (10') – Define latent heat, specific latent heat, introduce the formula \(Q = mL\) and the two types \(L_f\) and \(L_v\).
- Demonstration (8') – Melt ice and boil water while measuring temperature; discuss why temperature remains constant.
- Guided practice (12') – Work through the “Melting Ice” example together, highlighting substitution of \(L_f\).
- Independent practice (10') – Students solve the “Boiling Water” problem on the worksheet; teacher circulates for support.
- Concept check (5') – Quick poll or exit‑ticket question: “State one key difference between \(L_f\) and \(L_v\).”
- Summary & reflection (5') – Recap the main points and address any misconceptions.
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Conclusion:
Summarise that specific latent heat quantifies energy needed for phase changes without temperature change and that \(L_v\) is always larger than \(L_f\). Collect exit tickets to gauge understanding, and assign homework: complete a set of mixed problems involving both fusion and vaporisation calculations.
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