In physics, particularly in the study of motion (kinematics), precisely defining an object's location and how it moves is crucial. We'll explore three fundamental concepts: position, displacement, and distance. These terms are often used interchangeably in everyday language, but in physics, they have distinct and important meanings.

Position refers to the location of an object relative to a chosen reference point or origin. It's a vector quantity, meaning it has both magnitude and direction. We typically represent position using a coordinate system (e.g., x, y, z axes). For one-dimensional motion, we often use a single axis, like the x-axis, where positive values might indicate movement to the right and negative values to the left.

Displacement is the change in an object's position. It is also a vector quantity, defined as the straight-line distance and direction from the initial position to the final position. Displacement only cares about the start and end points, not the path taken.

Mathematically, displacement ($\Delta x$) is calculated as: $\Delta x = x_{final} - x_{initial}$

Distance, on the other hand, is a scalar quantity that measures the total length of the path traveled by an object. It does not consider direction. If an object moves back and forth, the distance traveled accumulates, even if its displacement returns to zero.

Consider a car moving 5 meters east and then 5 meters west.

• Its initial position might be 0 m.
• Its final position is 0 m.
• Its displacement is $0 ext{ m} - 0 ext{ m} = 0 ext{ m}$.
• The distance traveled is $5 ext{ m} + 5 ext{ m} = 10 ext{ m}$.

Understanding the distinction between distance and displacement is fundamental for solving problems involving speed, velocity, and acceleration. Many JEE Physics questions will test your ability to differentiate these concepts, especially in scenarios involving circular motion, back-and-forth movement, or complex paths. Always pay close attention to whether the question asks for distance or displacement.