**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, meaning it has both magnitude and direction (toward the center of the gravitational body). It 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:** Mass is measured in kilograms (kg), while weight is measured in newtons (N). - **Dependence on Gravity:** Mass remains constant regardless of location, while weight can change depending on the gravitational field strength. 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 varies with the location of the object, while weight remains constant everywhere." - This statement is incorrect because mass does not vary with location; it is constant. Weight, however, does vary with location due to changes in gravitational acceleration. For instance, an object weighs less on the Moon than on Earth. - **Option C:** "Mass is measured in newtons, while weight is measured in kilograms." - This option is incorrect because it confuses the units of mass and weight. Mass is measured in kilograms (kg), while weight is measured in newtons (N). This is a fundamental distinction in physics. - **Option D:** "Mass can change with temperature, while weight is always constant regardless of temperature." - This statement is misleading. Mass does not change with temperature under normal conditions; it remains constant. Weight can change with temperature indirectly if the temperature affects the gravitational field (which is negligible in most practical scenarios). However, the primary reason weight changes is due to changes in gravitational acceleration, not temperature. ### Summary of Key Points: - **Mass** is the amount of matter in an object and is constant regardless of location. - **Weight** is the force of gravity acting on that mass and varies with the strength of the gravitational field. - Mass is measured in **kilograms (kg)**, while weight is measured in **newtons (N)**. - Understanding the distinction between mass and weight is crucial for solving problems in physics related to forces and motion.