Choose the correct option for each question. There is only one correct response for each question.
How does the use of wheels help in reducing friction?

Options

A. By decreasing the roughness of the surface.
B. An increase in the roughness of the surface
C. An increase in the area of contact
D. A decrease in the area of contact.

Answer

To solve the question "How does the use of wheels help in reducing friction?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Friction Types**:
- There are two main types of friction: sliding friction and rolling friction. Sliding friction occurs when an object slides over a surface, while rolling friction occurs when an object rolls over a surface.

2. **Effect of Wheels**:
- When wheels are used, the motion of the vehicle is primarily rolling rather than sliding. This means that the contact between the wheels and the surface is not continuous like in sliding, but rather intermittent.

3. **Comparison of Friction**:
- Sliding friction is generally greater than rolling friction. This is because, in sliding, the entire surface area of the object is in contact with the ground, leading to more resistance. In contrast, with rolling, only a small part of the wheel is in contact with the ground at any given time.

4. **Conclusion**:
- Since rolling friction is less than sliding friction, the use of wheels reduces the overall friction experienced by the vehicle. Therefore, wheels help in reducing friction by allowing the object to roll instead of slide.

5. **Choosing the Correct Option**:
- Based on the explanation, the correct option would be related to the concept of rolling friction being less than sliding friction. The correct response would be that the use of wheels reduces friction by converting sliding friction into rolling friction.

### Final Answer:
The correct option is: **Wheels reduce friction by converting sliding friction into rolling friction**.

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