| Lesson Plan |
| Grade: |
Date: 01/12/2025 |
| Subject: Physics |
| Lesson Topic: understand that objects moving against a resistive force may reach a terminal (constant) velocity |
Learning Objective/s:
- Describe how resistive forces affect motion and lead to terminal velocity.
- Derive the expressions for terminal velocity for linear and quadratic drag.
- Calculate terminal velocity for given masses and drag coefficients.
- Explain why acceleration is zero when terminal speed is reached.
- Apply momentum concepts to analyze falling objects experiencing drag.
|
Materials Needed:
- Projector and screen
- Whiteboard and markers
- Printed worksheet with example problem
- Graphing calculators
- Short video of a sky‑diver/falling objects
|
Introduction:
Begin by asking students how a sky‑diver feels when they stop accelerating. Review Newton’s three laws to connect prior knowledge. Explain that today they will discover why objects reach a constant speed when resistive forces balance weight, and they will be able to predict that speed.
|
Lesson Structure:
- Do‑now (5'): Quick quiz on Newton’s laws (paper).
- Mini‑lecture (10'): Recap Newton’s laws, introduce resistive forces, show diagram of forces on a falling object.
- Derivation activity (12'): Guided derivation of terminal velocity for linear drag, then extend to quadratic drag.
- Guided practice (10'): Pair work solving the worksheet example (steel sphere), teacher circulates.
- Concept check (5'): Think‑pair‑share answering why acceleration is zero at terminal speed.
- Extension (8'): Discuss real‑world examples (sky‑diving, raindrops) and the role of Reynolds number.
- Summary (5'): Consolidate key equations on board; students copy into notes.
|
Conclusion:
Summarise that terminal velocity occurs when weight equals the resistive force, leaving acceleration at zero while motion continues. For exit, students write the condition “mg = Fₙₑₜ” on a sticky note. Assign homework: complete additional problems on terminal speed for both linear and quadratic drag.
|