A person starts walking and comes back to its initial position after 2 h, then which of the following quantity is zero?

Options

A. Path length
B. Average speed
C. Displacement
D. Time

Answer

To solve the problem, we need to analyze the motion of the person who starts walking and returns to the initial position after 2 hours.

### Step-by-Step Solution:

1. **Understanding the Motion**:
- The person starts from a specific point (let's call it Point A) and walks away from it. After some time, they turn around and walk back to Point A.

2. **Identifying Key Terms**:
- **Distance**: This is the total path length covered by the person during their journey.
- **Displacement**: This is defined as the shortest straight-line distance from the initial position to the final position, along with the direction.

3. **Analyzing the Journey**:
- Since the person returns to their starting point (Point A) after 2 hours, the final position is the same as the initial position.

4. **Calculating Displacement**:
- Since the initial and final positions are the same, the displacement is calculated as:
\[ \text{Displacement} = \text{Final Position} - \text{Initial Position} = \text{Point A} - \text{Point A} = 0 \]

5. **Conclusion**:
- The displacement of the person is zero because they ended up at the same point where they started. Therefore, the quantity that is zero in this scenario is **displacement**.

### Final Answer:
The quantity that is zero is **displacement**.