**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 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. **Why Option A is Correct:** - Option A correctly states that mass measures the amount of matter, while weight is the gravitational force acting on that mass. This distinction is crucial in physics, as it helps us understand how objects behave under different gravitational conditions. ### Why the Other Options are Incorrect: - **Option B: Mass changes with the location of the object, while weight remains constant.** - This statement is incorrect because mass does not change with location; it remains constant regardless of where the object is in the universe. Weight, however, does 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. - **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). This is a fundamental distinction in physics, as mixing these units can lead to significant misunderstandings in calculations. - **Option D: Mass is only relevant on Earth, while weight applies in all environments.** - This statement is misleading. Mass is a universal property of matter and is relevant everywhere in the universe. Weight, while it does apply in all environments, varies depending on the local gravitational field. For instance, an object has mass whether it is on Earth, Mars, or in a vacuum, but its weight will differ based on the gravitational force acting on it. ### 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, especially those involving gravitational forces.