Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: Describe how temperature, surface area and air movement over a surface affect evaporation
Learning Objective/s:
  • Describe how temperature influences the rate of evaporation.
  • Explain the effect of surface area on evaporation rate.
  • Analyse how air movement (wind) modifies evaporation.
  • Apply the qualitative evaporation equation to predict changes.
  • Evaluate real‑world examples such as drying clothes or spills.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint/slide deck
  • Printed worksheet with diagram and questions
  • Shallow tray of water and a deeper bowl
  • Fan or handheld blower
  • Thermometer
  • Stopwatch
  • Ruler (to measure surface area)
 Introduction:
Begin with a quick demonstration: a damp cloth left on the bench and another placed under a fan. Ask students what they notice and link observations to prior knowledge about kinetic energy and surface exposure. Explain that today they will investigate how temperature, surface area, and airflow control evaporation, and they will be able to predict the rate using a simple formula.
Lesson Structure:
  1. Do‑now (5'): Students write a brief explanation of why a puddle disappears faster on a sunny day than in shade; collect responses.
  2. Mini‑lecture (10'): Present key concepts and the qualitative equation, using slides and the suggested diagram.
  3. Demonstration (10'): Show water in a shallow tray vs a deep bowl, heat one with a lamp, fan the other; students record observations and timing.
  4. Guided analysis (10'): In pairs, calculate relative evaporation rates using the equation and discuss each factor’s contribution.
  5. Worksheet activity (10'): Complete questions linking factors to kinetic energy, surface area, and concentration gradient; teacher circulates.
  6. Quick check (5'): Exit ticket – one sentence stating which factor has the greatest impact and why.
Conclusion:
Summarise that higher temperature, larger surface area, and stronger airflow each increase evaporation by boosting kinetic energy, exposure, or removing saturated vapour. Ask students to write an exit ticket summarising the most influential factor for a given scenario. Assign homework to observe and record evaporation rates of a water dish at home, noting temperature and airflow.