We use sliding friction when we write with a pencil. Discuss how

Explanation

### Step-by-Step Solution:

1. **Understanding Sliding Friction**: Sliding friction occurs when two surfaces slide against each other. In the case of writing with a pencil, the pencil's tip slides over the surface of the paper.

2. **Initiating Writing**: When you begin to write, the pencil is pressed against the paper. This creates a contact between the pencil and the paper, allowing for friction to occur.

3. **Relative Motion**: As you move the pencil across the paper, there is relative motion between the pencil and the paper. The pencil moves while the paper remains stationary, which is essential for sliding friction to take place.

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