a book is at rest on a table. identify the correct free - body diagram for this situation
a book is at rest on a table. identify the correct free - body diagram for this situation
Answer
Explanation:
Step1: Analyze forces on book
The book at rest on the table has two forces acting on it. The force of gravity $F_g$ acts down - ward and the normal force $F_N$ exerted by the table acts upward. There is no frictional force $F_f$ as there is no relative motion or tendency of relative motion.
Step2: Check free - body diagrams
In the first diagram, the normal force $F_N$ is shown in the wrong direction (it should be upward). In the second diagram, there is an incorrect frictional force $F_f$ shown (no friction in this situation). In the third diagram, the force of gravity $F_g$ acts downward and the normal force $F_N$ acts upward which is correct for a book at rest on a table.
Answer:
The third free - body diagram (where $F_g$ acts downward and $F_N$ acts upward) is the correct one.