Choose the correct option for each question. There is only one correct response for each question.
Which of these is both an advantage and a disadvantage of friction?

Options

A. Friction causes wear and tear
B. Friction helps us to walk
C. Friction helps us to write
D. Friction produces heat

Answer

To solve the question, we need to analyze each option provided and determine which one represents both an advantage and a disadvantage of friction.

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify which option describes a characteristic of friction that can be seen as both beneficial and harmful.

2. **Analyze Each Option**:
- **Option 1: Friction causes wear and tear.**
- This is primarily a disadvantage because wear and tear can lead to damage of materials. There is no advantage associated with this.

- **Option 2: Friction helps us to walk.**
- This is an advantage. Friction between our shoes and the ground allows us to walk without slipping. There is no disadvantage mentioned here.

- **Option 3: Friction helps us to write.**
- This is also an advantage. The friction between the pen/pencil and the paper allows us to write. Again, there is no disadvantage noted.

- **Option 4: Friction produces heat.**
- This is both an advantage and a disadvantage. The advantage is that friction can generate heat, which can be beneficial (like warming our hands when rubbing them together). The disadvantage is that excessive friction can lead to overheating of machine parts, which can cause damage.

3. **Choose the Correct Option**: Based on the analysis, **Option 4: Friction produces heat** is the only option that represents both an advantage and a disadvantage.

### Final Answer:
The correct option is **Option 4: Friction produces heat**.

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