Lesson Plan

• Define gravitational potential at a point as the work done per unit mass in bringing a test mass from infinity.
• Explain how gravitational potential relates to potential energy and the gravitational field.
• Apply the formula φ = ‑GM/r to calculate the potential for given masses and distances.
• Distinguish between the scalar nature of potential and the vector nature of the field, addressing common misconceptions.
• Use gravitational potential to solve simple numerical problems (e.g., Earth’s surface potential).

• Projector and screen
• Whiteboard and markers
• Physics textbook (A‑Level)
• Worksheet with practice problems
• Scientific calculators
• Printed diagram of a test mass moving from infinity to distance r
• Access to an online gravity‑potential simulation (optional)

Begin with a quick question: “If you lift a mass higher, what happens to the work you must do?” Connect this to prior knowledge of work and energy. State that today’s success criteria are to define gravitational potential, derive its formula, and use it in calculations.

1. Do‑now (5 min): Short written response on work done against gravity.
2. Mini‑lecture (10 min): Define gravitational potential, introduce reference at infinity, derive φ = ‑GM/r with board work.
3. Guided example (10 min): Calculate Earth’s surface potential; students follow step‑by‑step.
4. Interactive simulation (8 min): Explore how φ changes with distance using an online tool.
5. Misconception check (5 min): Think‑pair‑share on why potential can be negative.
6. Practice worksheet (12 min): Students solve three problems while teacher circulates.
7. Exit‑ticket quiz (5 min): Write the definition of gravitational potential and one real‑world example.

Recap the definition and the key formula, emphasizing its scalar nature and the role of the infinity reference. Collect exit tickets to gauge understanding, and assign homework: complete the remaining worksheet problems and read the textbook section on gravitational fields.