Competency #1
Answer and Explanation
The inertia of the book is unchanged.
Inertia is a property of an object that is a measurement of the objects ability to resist changes in motion. The inertia in an object is related to the amount of mass an object has. The greater the amount of mass, the greater the inertia.
Thus, a grain of sand is easier to get moving than a large boulder would be, because the boulder has more mass and thus more inertia.
Similarly, if the boulder and sand are both coming toward you, the boulder is going to be much harder to stop, because it has more inertia.
However, the amount of inertia any one object has is not related to whether or not the object is currently moving. The amount of inertia a grain of sand has is the same whether it is lying on the beach or blowing in the wind. An object's inertia does not change unless the mass of the object changes.