**Correct Option: A. Mass is the amount of matter in an object, while weight is the force exerted on that mass by gravity.** ### Detailed Explanation: 1. **Understanding Mass:** - Mass is a measure of the amount of matter in an object. It is a scalar quantity, which means it has magnitude but no direction. The standard unit of mass in the International System of Units (SI) is the kilogram (kg). - Mass is an intrinsic property of an object; it does not change regardless of the object's location in the universe. For example, a 10 kg object on Earth has the same mass as a 10 kg object on 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 a vector quantity, which means it has both magnitude and direction (the direction is towards the center of the gravitational body, like Earth). - The formula for weight (W) is given by: \[ W = m \cdot g \] where \( m \) is the mass of the object and \( g \) is the acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \) on Earth). - Since the value of \( g \) can change depending on where you are (for example, it is less on the Moon than on Earth), the weight of an object can vary based on its location. 3. **Why Option A is Correct:** - Option A accurately describes the fundamental difference between mass and weight. Mass is a measure of matter, while weight is the gravitational force acting on that mass. This distinction is crucial in physics and helps in understanding concepts related to force, motion, and gravity. ### Why the Other Options are Incorrect: - **Option B: Mass changes with the location of the object, while weight remains constant regardless of location.** - This statement is incorrect because mass does not change with location; it remains constant. Weight, however, does change with location due to variations in gravitational acceleration. For example, an object weighs less on the Moon than on Earth because the Moon's gravitational pull is weaker. - **Option C: Mass is measured in newtons, while weight is measured in kilograms.** - This option is incorrect because it confuses the units of measurement. Mass is measured in kilograms (kg), while weight is measured in newtons (N). The newton is the unit of force, which is appropriate for weight since it is a force due to gravity. - **Option D: Mass is a scalar quantity, while weight is a vector quantity that only has magnitude.** - This statement is partially correct but misleading. While it is true that mass is a scalar quantity and weight is a vector quantity, weight has both magnitude and direction (towards the center of the gravitational body). Therefore, saying it "only has magnitude" is incorrect. ### Summary of Key Points: - **Mass** is the amount of matter in an object and is constant regardless of location; it is measured in kilograms (kg). - **Weight** is the force due to gravity acting on that mass and can change based on location; it is measured in newtons (N). - Mass is a scalar quantity (magnitude only), while weight is a vector quantity (magnitude and direction). - Understanding the distinction between mass and weight is essential for solving problems related to forces and motion in physics.