**Correct Option: B. Mass is a measure of the amount of matter in an object, while weight is the force exerted by gravity on that mass.** ### Detailed Explanation: 1. **Understanding Mass:** - Mass is a fundamental property of matter. It quantifies the amount of matter 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 10 kg object has a mass of 10 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, meaning it has both magnitude and direction (toward the center of the gravitational body). Weight is measured in newtons (N). 3. **Key Differences:** - **Dependence on Gravity:** Mass remains constant regardless of location, while weight varies depending on the gravitational field strength. For example, an object with a mass of 10 kg will weigh about 98.1 N on Earth (using \( g = 9.81 \, \text{m/s}^2 \)), but only about 16.5 N on the Moon (where \( g \approx 1.63 \, \text{m/s}^2 \)). - **Units of Measurement:** Mass is measured in kilograms (kg), while weight is measured in newtons (N). This distinction is crucial in physics. ### Why Other Options Are Incorrect: - **Option A:** "Mass is dependent on gravity, while weight is constant regardless of location." - This statement is incorrect because mass is independent of gravity. It is weight that depends on gravity. Weight changes with the gravitational field strength, while mass does not. - **Option C:** "Mass is measured in newtons, while weight is measured in kilograms." - This option is incorrect because it reverses the definitions. Mass is measured in kilograms (kg), and weight is measured in newtons (N). This is a fundamental distinction in physics. - **Option D:** "Mass and weight are interchangeable terms that refer to the same physical quantity." - This statement is false. Mass and weight are distinct concepts in physics. They refer to different properties: mass is the amount of matter, while weight is the gravitational force acting on that mass. ### Common Pitfalls: - Confusing mass with weight is a common mistake. Remember that mass is a measure of how much matter is present, while weight is the force due to gravity acting on that mass. - Forgetting the units can lead to errors in calculations. Always ensure you are using the correct units: kg for mass and N for weight. ### Revision Summary: - Mass is the amount of matter in an object, measured in kilograms (kg). - Weight is the force of gravity acting on that mass, calculated using \( W = m \cdot g \) and measured in newtons (N). - Mass is constant regardless of location; weight varies with the strength of the gravitational field. - Mass and weight are not interchangeable; they represent different physical quantities.