The correct option is (c) 1 and 3 only.
Explanation
Motion is described using two fundamental physical quantities: distance and displacement. Distance is a scalar quantity representing the total length of the actual path covered by an object. Displacement is a vector quantity representing the shortest straight-line separation between the initial and final positions.
Statement-wise Analysis
- Statement 1 is Correct: The magnitude of displacement corresponds to the straight-line distance between two points. Geometrically, a straight line is the shortest path between two points. Therefore, the actual path length (distance) is always greater than or equal to the magnitude of displacement. It can never be less.
- Statement 2 is Incorrect: The magnitude of displacement is equal to the distance travelled only when the object moves along a straight line without changing direction. If the object moves in a curve or reverses its direction, the total distance travelled will be greater than the magnitude of displacement.
- Statement 3 is Correct: This statement defines the magnitude of displacement. It is strictly the length of the straight-line segment connecting the initial position to the final position, regardless of the complexity of the actual path taken.
Key Takeaway
Distance is path-dependent (Scalar), while Displacement depends only on the initial and final positions (Vector). Consequently, the relationship between their magnitudes is always: Magnitude of Displacement ≤ Distance.