You hold your physics textbook in your hand. (Assume that no other objects are in contact with the book.) a. Identify the forces acting on the book.

1. book on hand
2. hand on book
3. floor on book
4. earth on book

b. For each force you identified in part (a), indicate the direction. (If a force is not applicable, choose NA.)

1, book on hand
2. hand on book
3. floor on book
4. earth on book

a) Please see below as the answer is self-explanatory.

b) 1. vertically downward

   2. vertically upward

   3  N/A

   4  vertically downward.

Explanation:

a)

If the book is hold by the hand, this means (according to Newton's third law) that both exert a force on each other, equal and opposite.In this case this pair is formed by normal forces, the normal force (upward) that the hand does on the book (avoiding it to be accelerated downward) and the normal force that the book does on the hand (downward) avoiding it to be accelerated in the upward direction.The other force that acts on the book is the one due to gravity, and is always downward, which is numerically equal to the normal force that the hand does on the book, due to the book is at rest. There is no interaction between the book and the floor, so there is no force between them, neglecting the gravitational attraction between their masses.