Carla demonstrates Newton’s First Law of Motion by slowly pushing a book across a table. The book moves at a constant rate of speed so long as she is pushing it. Which of the following is NOT true?

Question

The upward force exerted by the table balances the book’s weight.
There is an unbalanced force on the book, acting in the direction of motion.
Her push balances the force of friction.
The forces acting on the book are all balanced.

Answer 1

The statement that is NOT true is:

There is an unbalanced force on the book, acting in the direction of motion.

In this scenario, since the book is moving at a constant rate of speed while being pushed, it indicates that the forces acting on the book are balanced. The upward force from the table balances the weight of the book, and Carla's push exactly balances the force of friction opposing the motion. Therefore, no unbalanced force is acting on the book; it remains in a state of constant velocity, in accordance with Newton's First Law of Motion, which states that an object in motion will remain in motion at a constant velocity unless acted upon by an unbalanced force.