Lesson Plan

• Describe weight as the gravitational force acting on a mass.
• Explain how weight varies with the local acceleration due to gravity and how it differs from mass.
• Calculate the weight of objects on Earth and other celestial bodies using W = mg.
• Apply the weight concept to analyse vertical momentum changes in free‑fall situations.
• Identify and correct common misconceptions about weight versus mass.

• Projector and screen
• Whiteboard and markers
• Printed worksheet with weight problems
• Scientific calculators
• Set of masses and a spring scale
• Diagram of a free‑falling object (handout or slide)

Begin with a short video clip showing astronauts “jumping” on the Moon to spark curiosity about why they feel lighter. Ask students to recall the definitions of mass and force from previous lessons. State that by the end of the lesson they will be able to describe weight, compute it for different gravities, and link it to momentum changes.

1. Do‑Now (5 min): Quick written question – “If mass stays the same, why does weight change on the Moon?” Collect responses.
2. Mini‑lecture (10 min): Introduce W = mg, discuss direction of weight, and show the vector form.
3. Demonstration (8 min): Use a spring scale with a 2 kg mass; first measure weight on Earth, then simulate Moon gravity by scaling the reading (≈1/6).
4. Guided Practice (12 min): Students work in pairs on worksheet calculations for Earth, Moon, and a hypothetical planet.
5. Concept‑Check (5 min): Think‑pair‑share on the three common misconceptions listed in the notes.
6. Summary & Check for Understanding (5 min): Teacher revisits the checklist, students write one key takeaway on a sticky note.

Summarise that weight is a force given by W = mg, varies with g, and always points downward. For the exit ticket, ask each student to write the weight of a 60 kg object on the Moon. Assign homework: complete additional weight‑calculation problems for Earth, Mars, and Jupiter.