The correct option is **C. Displacement**. ### Detailed Explanation 1. **Understanding Scalars and Vectors**: - In physics, quantities are classified into two categories: scalars and vectors. - **Scalars** are quantities that have only magnitude (size) and no direction. Examples include temperature, mass, and time. - **Vectors**, on the other hand, have both magnitude and direction. Displacement is a prime example of a vector quantity. 2. **Analyzing Each Option**: - **A. Temperature**: - Temperature is a scalar quantity. It tells us how hot or cold something is but does not have a direction associated with it. For example, saying the temperature is 30 degrees Celsius does not imply any direction. - **B. Mass**: - Mass is also a scalar quantity. It measures the amount of matter in an object and is expressed in units like kilograms (kg). Mass does not have a direction; it simply tells us how much matter is present. - **C. Displacement**: - Displacement is a vector quantity. It refers to the change in position of an object and is defined as the shortest distance from the initial position to the final position, along with the direction of that line. For example, if an object moves from point A to point B, the displacement is not just the distance traveled but also the direction from A to B. - Mathematically, displacement can be represented as a vector: **\(\vec{d} = \vec{r_f} - \vec{r_i}\)**, where \(\vec{r_f}\) is the final position vector and \(\vec{r_i}\) is the initial position vector. - **D. Time**: - Time is a scalar quantity. It measures the duration of events and is expressed in units like seconds (s). Time does not have a direction; it simply indicates how long something lasts. 3. **Why Other Options Are Incorrect**: - Options A, B, and D are all scalar quantities, which means they lack the directional component that defines vector quantities. This is a fundamental distinction in physics that helps in understanding motion and forces. ### Common Pitfalls - Students often confuse scalar and vector quantities, especially when they think about physical situations. Remember that direction is key for vectors. - It’s important to visualize the difference: for displacement, you can draw an arrow from the starting point to the endpoint, indicating both distance and direction, while for scalars, you can only state a value without any directional context. ### Revision Summary - **Scalars** have only magnitude (e.g., temperature, mass, time). - **Vectors** have both magnitude and direction (e.g., displacement). - Displacement is the only vector quantity among the options provided. - Understanding the distinction between scalars and vectors is crucial in physics, especially in topics related to motion and forces.