If an external force and the frictional force acting on a body cancel each other and keep the body at rest, the frictional force is

Options

A. Rolling friction
B. Sliding friction
C. Static friction
D. None

Answer

To solve the question, we need to analyze the forces acting on the body and understand the concept of friction.

### Step-by-Step Solution:

1. **Understanding the Situation**:
- The body is at rest, which means the net force acting on it is zero.
- There are two forces acting on the body: an external force (let's call it \( F \)) and the frictional force (let's call it \( f \)).

2. **Applying Newton's First Law**:
- According to Newton's First Law of Motion, if a body is at rest, the sum of all forces acting on it must be zero.
- This can be expressed mathematically as:
\[ F - f = 0 \]
- Rearranging this gives us:
\[ F = f \]

3. **Identifying the Type of Friction**:
- The frictional force that opposes the external force and keeps the body at rest is known as static friction.
- Static friction acts when an object is not moving and prevents it from starting to move when an external force is applied.

4. **Conclusion**:
- Since the external force and the frictional force are equal and opposite, and the body remains at rest, we conclude that the frictional force in this scenario is static friction.

5. **Final Answer**:
- The frictional force is static friction.