When a conservation force does positive work on a body, then the

Options

A. Potential energy of body increases
B. Potential energy of body decreases
C. Total mechanical energy of body increases
D. Total mechanical energy of body decreases

Answer

To solve the question, "When a conservative force does positive work on a body, then the...", we will analyze the relationship between work done by conservative forces and changes in potential energy.

### Step-by-Step Solution:

1. **Understanding Conservative Forces**:
- Conservative forces are forces where the work done is independent of the path taken and depends only on the initial and final positions. Examples include gravitational force and spring force.

2. **Work Done by Conservative Forces**:
- The work \( W \) done by a conservative force can be expressed in terms of potential energy \( U \) as:
\[ W = U_{\text{initial}} - U_{\text{final}} \]
- If the work done \( W \) is positive, this implies:
\[ U_{\text{initial}} > U_{\text{final}} \]
- This means that the potential energy of the system is decreasing.

3. **Interpreting the Change in Energy**:
- Since the potential energy decreases when positive work is done, the energy lost in potential energy is converted into kinetic energy. Thus, the kinetic energy of the body will increase.

4. **Conclusion**:
- Therefore, when a conservative force does positive work on a body, the potential energy of the body decreases.

### Final Answer:
When a conservative force does positive work on a body, the potential energy of the body decreases.

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