The frictional force between two surfaces is independent of

Options

A. Nature of the surface
B. Size of the body
C. Area of contact
D. Mass of the body

Answer

To solve the question regarding the factors that the frictional force between two surfaces is independent of, we can analyze each option provided:

### Step-by-step Solution:

1. **Understanding Friction**:
Friction is a force that opposes the relative motion of two surfaces in contact. It depends on various factors, including the nature of the surfaces and the normal force acting between them.

2. **Analyzing the Options**:
- **Option A: Nature of the Surface**:
The frictional force is dependent on the nature of the surfaces in contact (e.g., rough vs. smooth). Therefore, this option is not correct.

- **Option B: Size of the Body**:
The size of the body does not affect the frictional force directly. Friction depends on the normal force and the coefficient of friction, not on the size of the object. Thus, this option is correct.

- **Option C: Area of Contact**:
While it might seem intuitive that a larger area would increase friction, in reality, for rigid bodies, the frictional force does not depend on the area of contact. The pressure (force per unit area) adjusts such that the total friction remains constant. Thus, this option is also correct.

- **Option D: Mass of the Body**:
The mass of the body affects the normal force (which is equal to the weight of the body under gravity), and since friction is proportional to the normal force, this means that friction is dependent on mass. Therefore, this option is not correct.

3. **Conclusion**:
The frictional force between two surfaces is independent of:
- Size of the body (Option B)
- Area of contact (Option C)

Thus, the correct answers are **B and C**.

### Final Answer:
The frictional force between two surfaces is independent of the size of the body and the area of contact.