You can keep a book pressed against a wall and prevent it from falling down. Can this horizontal force applied cancel the weight which is a vertical force? Explain.

Explanation

To understand how a book can be kept pressed against a wall without falling, we need to analyze the forces acting on the book. Here’s a step-by-step solution:

### Step 1: Identify the Forces Acting on the Book
When a book is pressed against a wall, there are several forces acting on it:
- **Weight (W)**: This is the downward force due to gravity acting on the book.
- **Normal Force (N)**: This is the force exerted by the wall on the book, acting perpendicular to the wall.
- **Frictional Force (f)**: This is the force that opposes the motion of the book sliding down the wall. It acts upward when the book is pressed against the wall.

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