The acceleration of the book is due to gravity and is approximately 9.8 m/s² regardless of its mass or the height from which it is dropped.

Here's why:

* Gravity: Near the Earth's surface, all objects experience a constant acceleration due to gravity, which is approximately 9.8 m/s². This means that their velocity increases by 9.8 meters per second every second they fall.

* Mass and Acceleration: While the mass of the book affects its potential energy (how much energy it has due to its height), it doesn't affect the rate at which it accelerates downwards.

Therefore, the book's acceleration is approximately 9.8 m/s².