A body is moving along a straight line path with constant velocity. At an instant of time the distance travelled by it is S and its displacement is D, then

Options

A. `D lt S`
B. `D gt S`
C. `D = S`
D. `D lt= S`

Explanation

To solve the problem, we need to understand the concepts of distance and displacement in the context of motion along a straight line with constant velocity.

### Step-by-Step Solution:

1. **Understanding Distance and Displacement**:
- **Distance (S)**: This is the total length of the path traveled by the body, regardless of direction. It is a scalar quantity.
- **Displacement (D)**: This is the shortest distance from the initial position to the final position of the body in a specific direction. It is a vector quantity.

2. **Constant Velocity**:
- Since the body is moving with constant velocity, it means that the speed of the body does not change over time, and it moves in a straight line.

3. **Relationship Between Distance and Displacement**:
- In the case of straight-line motion with constant velocity, the distance traveled (S) and the displacement (D) can be related as follows:
- If the body moves in a straight line without changing direction, then the distance traveled will be equal to the displacement.
- Therefore, we can conclude that \( S = D \).

4. **Conclusion**:
- Since the body is moving along a straight line path with constant velocity, the distance traveled (S) is equal to the displacement (D). Thus, we can write:
\[ S = D \]

### Summary:
In summary, for a body moving in a straight line with constant velocity, the distance traveled (S) is equal to the displacement (D).