what do you understand by rolling friction. Give two examples

Explanation

### Step-by-Step Solution:

1. **Definition of Rolling Friction**:
Rolling friction is the resistance that occurs when an object rolls over a surface. Unlike sliding friction, which occurs when two surfaces slide against each other, rolling friction occurs when a round object, such as a wheel or sphere, rolls forward while rotating.

2. **Characteristics of Rolling Friction**:
- In rolling motion, there is a specific point of contact between the rolling body and the surface.
- The point of contact changes as the object rolls, which minimizes the area of contact and reduces the frictional force.
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