Lesson Plan

• Describe why the acceleration due to gravity (g) can be treated as constant near Earth’s surface.
• Apply the kinematic equations with a constant acceleration of g to solve free‑fall problems.
• Analyse typical free‑fall situations (dropped, thrown upwards, thrown downwards) and select the appropriate equations.
• Identify and correct common misconceptions about free fall and the role of air resistance.

• Projector and screen
• Whiteboard and markers
• Small ball or marble
• Stopwatch (or phone timer)
• Ruler or measuring tape
• Worksheets with practice questions
• Calculators (one per pair)

Begin with a quick video of a ball being dropped from different heights to spark curiosity. Ask students what they think controls the speed of the fall and link it to prior knowledge of acceleration. State that by the end of the lesson they will be able to predict motion using a single constant value, g.

1. Do‑now (5') – short quiz on previous velocity‑acceleration concepts.
2. Mini‑lecture (10') – introduce constant g, its numerical value, direction, and why it is approximately constant.
3. Demonstration (8') – drop the ball, time the fall, compare measured time with the calculation using g = 10 m s⁻².
4. Guided practice (12') – students work in pairs on the worksheet: identify the situation, choose the correct equation, and solve for unknowns.
5. Check for understanding (5') – misconception poll (e.g., “Free fall only means falling straight down”).
6. Summary & exit ticket (5') – each student writes one key takeaway and solves a final quick problem on a sticky note.

Recap that g ≈ 9.8 m s⁻² (rounded to 10 m s⁻² for exams) and that it allows us to treat a wide range of motions as uniformly accelerated. Collect the exit tickets to gauge understanding and assign a short homework set of three free‑fall problems for reinforcement.