Rolling friction is____than sliding friction.

Options

A. Smaller
B. greater
C. Smaller as well as greater
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding the Types of Friction:**
- Friction is the force that opposes the relative motion of two surfaces in contact. There are different types of friction, including static friction, sliding friction, and rolling friction.

2. **Defining Rolling Friction:**
- Rolling friction occurs when an object rolls over a surface. For example, when a wheel rolls on the ground, the contact area is small, and the surfaces do not interlock as much compared to sliding.

3. **Defining Sliding Friction:**
- Sliding friction occurs when an object slides over a surface. In this case, the surfaces are in contact for a longer duration, which allows for more interlocking of the surface irregularities.

4. **Comparing Rolling and Sliding Friction:**
- Since rolling friction involves less contact area and less interlocking of surfaces, it results in a smaller frictional force compared to sliding friction, where the surfaces are in contact for a longer time and interlock more.

5. **Conclusion:**
- Therefore, we conclude that rolling friction is **smaller** than sliding friction.

**Final Answer:**
Rolling friction is **smaller** than sliding friction.

---