Above this minimum vertical distance, the gravity potential is not negligible

Options

A. 1 m
B. 5 m
C. 10 m
D. 20 m

Answer

To solve the question regarding the minimum vertical distance above which the gravitational potential is not negligible, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gravity Potential**:
- Gravity potential is the potential energy per unit mass that an object possesses due to its height in a gravitational field. It is influenced by the height of the water column, the density of the water, and the acceleration due to gravity.

2. **Identifying the Options**:
- The options provided are 1 meter, 5 meters, 10 meters, and 20 meters. We need to determine at which height the gravitational potential becomes significant.

3. **Analyzing the Concept**:
- At lower heights, the effect of gravity on water potential can be considered negligible. This means that for small heights, the gravitational potential does not significantly affect the overall water potential.

4. **Determining the Minimum Height**:
- Based on the information provided, it is indicated that above a height of 5 meters, the gravitational potential is not negligible. This implies that at heights less than 5 meters, the gravitational potential can be ignored.

5. **Conclusion**:
- Therefore, the correct answer to the question is **5 meters**. This is the minimum vertical distance above which the gravitational potential must be considered.

### Final Answer:
**5 meters**