| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: Qualitative understanding of frictional forces and viscous/drag forces including air resistance (no treatment of coefficients required; simple model of drag increasing with speed) |
Learning Objective/s:
- Describe the difference between static and kinetic friction and identify the direction of the frictional force.
- Explain how viscous and pressure drag arise and why they increase with speed.
- Apply a simple piece‑wise drag model to predict the behaviour of an object moving through a fluid.
- Compare and contrast frictional forces on solid surfaces with drag forces in fluids.
- Analyse a basic problem to determine terminal speed using the qualitative drag model.
|
Materials Needed:
- Projector and screen
- Whiteboard and markers
- Diagram handouts of an inclined plane and a sphere in air
- Block, inclined plane, and spring scale for friction demo
- Small spheres and a fan or drop‑tube for drag demonstration
- Worksheet with comparative friction/drag problems
- Calculators
|
Introduction:
Begin with a quick question: “What stops a sliding book or a falling feather?” Connect this to students’ prior knowledge of Newton’s second law and the idea of forces opposing motion. State that by the end of the lesson they will be able to qualitatively explain both friction and drag and predict how speed changes under these forces.
|
Lesson Structure:
- Do‑now (5'): Recall Newton’s second law and write the definition of friction.
- Mini‑lecture (10'): Static vs kinetic friction, diagram of block on an incline, direction of force.
- Demonstration (10'): Block on inclined plane with spring scale to feel frictional force.
- Intro to drag (8'): Explain viscous vs pressure drag, show short video of a sphere falling through air.
- Interactive modelling (12'): Develop the piece‑wise drag model on the board; students predict terminal speed.
- Guided practice (15'): Worksheet problems comparing friction and drag scenarios.
- Check for understanding (5'): Concept questions using clickers or hand‑raise.
|
Conclusion:
Summarise that friction opposes relative motion between solids and is largely speed‑independent, whereas drag opposes motion through fluids and grows with speed. Ask students to write one key takeaway on an exit ticket and assign a short homework: analyse a real‑world example (e.g., a cyclist or a falling leaf) using the qualitative drag model.
|