Topic: Mass and Weight
Lesson 1: Mass and Weight Concepts
| Section | Details |
|---|---|
| Objective | – Define mass as a measure of the quantity of matter in an object.- State that weight is the gravitational force on an object. |
| Activities | – Starter (5 mins): Show a balance and a spring scale, and ask: “What is the difference between mass and weight?”- Main (25 mins): 1. Mass vs. Weight: – Mass is a scalar, constant everywhere. – Weight is a force depending on gravitational pull. 2. Gravitational Field Strength (gg): – Explain g=Wmg = \frac{W}{m}. – Students calculate weight for objects of different masses on Earth (g=9.8 m/s2g = 9.8 \, \text{m/s}^2). 3. Practical Activity: Compare the weight of the same object on different planets using given gg-values.- Plenary (10 mins): Discuss how weight changes in space (e.g., astronauts on the moon). |
| Resources | Balance, spring scale, worksheets, data on gg-values for different planets. |
| Time | 40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary). |
| Homework | Write an explanation of why weight changes but mass does not when traveling to different planets. |
| Assessment | Worksheet: Calculate weight for various masses using g=9.8 m/s2g = 9.8 \, \text{m/s}^2. |
| Past Paper Practice | IGCSE Physics 0625/12/O/N/20 Q4(a). |
Lesson 2: Using Gravitational Field Strength
| Section | Details |
|---|---|
| Objective | – Use g=Wmg = \frac{W}{m} to calculate weight, mass, or gravitational field strength.- Describe weight as the effect of a gravitational field on mass. |
| Activities | – Starter (5 mins): Ask: “If gravity on Mars is 3.7 m/s23.7 \, \text{m/s}^2, what would happen to your weight?”- Main (25 mins): 1. Formula Practice: – Students solve problems involving g=Wmg = \frac{W}{m}. – Example: Calculate weight on the moon (g=1.6 m/s2g = 1.6 \, \text{m/s}^2). 2. Gravitational Field Effects: – Discuss how weight changes in stronger and weaker gravitational fields. – Show videos of astronauts on the moon vs. Earth.- Plenary (10 mins): Students summarize key differences between mass and weight using diagrams. |
| Resources | Videos, calculators, worksheets with gg-value problems. |
| Time | 40 minutes total: 5 mins (Starter) + 25 mins (Main) + 10 mins (Plenary). |
| Homework | Research gg-values on other planets and calculate the weight of a 50kg person on each. |
| Assessment | Worksheet: Solve problems involving g=Wmg = \frac{W}{m}. |
| Past Paper Practice | IGCSE Physics 0625/32/M/J/21 Q5(b). |
Key Notes for Students:
- Mass vs. Weight:
- Mass is constant, weight depends on gravity.
- Practical Skills:
- Measure accurately using appropriate tools (e.g., balance, cylinder).
Notes for Teachers:
- Use practical examples to engage students (e.g., objects floating in water).
- Encourage group work during density experiments to build teamwork skills.
- Provide clear explanations for experimental methods.
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