**Correct Option: A. Mass is a measure of the amount of matter in an object, while weight is the force exerted by gravity on that object.** ### Detailed Explanation: 1. **Understanding Mass:** - Mass is a fundamental property of matter. It quantifies the amount of matter contained in an object and is usually measured in kilograms (kg) or grams (g). - Mass is an intrinsic property, meaning it does not change regardless of the object's location in the universe. For example, a 1 kg object has a mass of 1 kg whether it is on Earth, the Moon, or in space. 2. **Understanding Weight:** - Weight, on the other hand, is the force exerted on an object due to gravity. It is calculated using the formula: \[ W = m \cdot g \] where \( W \) is weight, \( m \) is mass, and \( g \) is the acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \) on Earth). - Weight is a vector quantity, which means it has both magnitude and direction (toward the center of the gravitational body). Weight is measured in newtons (N). 3. **Key Differences:** - **Nature of Measurement:** Mass measures the amount of matter, while weight measures the gravitational force acting on that matter. - **Units of Measurement:** Mass is measured in kilograms (kg), while weight is measured in newtons (N). - **Dependence on Gravity:** Mass remains constant regardless of location, while weight varies depending on the strength of the gravitational field. For example, an object weighs less on the Moon than on Earth due to the Moon's weaker gravitational pull. ### Why Other Options Are Incorrect: - **Option B:** "Mass is the force of gravity acting on an object, while weight is the amount of matter in that object." - This statement is incorrect because it reverses the definitions of mass and weight. Mass is not a force; it is a measure of matter. Weight is indeed the force due to gravity. - **Option C:** "Mass can change depending on location, while weight remains constant regardless of location." - This statement is incorrect. Mass does not change with location; it is constant. Weight changes with location because it depends on the local gravitational field strength. - **Option D:** "Mass is measured in newtons, while weight is measured in kilograms." - This statement is incorrect because it confuses the units. Mass is measured in kilograms (kg), while weight is measured in newtons (N). ### Common Pitfalls: - Confusing mass and weight is a common mistake. Remember that mass is a measure of how much matter is in an object, while weight is the force due to gravity acting on that mass. - Forgetting that weight can change based on location (e.g., on different planets) while mass remains constant. ### Revision Summary: - Mass is the amount of matter in an object (measured in kg). - Weight is the force of gravity acting on that mass (measured in N). - Mass is constant regardless of location; weight varies with gravitational strength. - Remember the formula: \( W = m \cdot g \) to calculate weight.