The force exerted on the book by the table refers to the normal force `F_N` .

Note that a normal force is always perpendicular to the surface of contact. It is always directed upward, too.

Since the book is lying on a stationary table which means that the surface is horizontal and not moving up or down. So normal force `(F_N)` is equal to downward force which is the weight `(W)` of the book.

Moreover, since the book is at rest the forces acting on the book are `F_N` and `W` only.

Using Newton's Law,

`sum F = 0`

Since `F_N` is the upward force and `W` is the downard force, their signs differ.

`F_N - W=0`

`F_N= W`

Note that weight is the product of mass of an object and gravity. The value of gravity in earth is 9.8 m/s^2 .

`F_N=mg`

`F_N = (1.75 kg)(9.8 m/s^2) = 17.15 N`

**Hence, the force exerted on the book by the table is 17.15 N and is directed upward.**

Posted on

## We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

- 30,000+ book summaries
- 20% study tools discount
- Ad-free content
- PDF downloads
- 300,000+ answers
- 5-star customer support

Already a member? Log in here.

Are you a teacher? Sign up now