There are five books in a stack,each with a weight of 8N.The coefficient of friction between all the books is 0.4 as is the coefficient between the table and the bottom book.What horizontal push must I just exceed on the next to bottom book to start sliding the top four books off the bottom one?
A) 3.2 N
B) 12.8 N
C) 1.6 N
D) 16 N
E) 32 N

Question

There are five books in a stack,each with a weight of 8N.The coefficient of friction between all the books is 0.4 as is the coefficient between the table and the bottom book.What horizontal push must I just exceed on the next to bottom book to start sliding the top four books off the bottom one?
A) 3.2 N
B) 12.8 N
C) 1.6 N
D) 16 N
E) ​32 N

Quizplus · Accepted Answer

The force of friction that needs to be overcome to slide the top four books off the bottom one is calculated as: Friction force = coefficient of friction * normal force. The normal force here is the weight of the top four books, which is 4 books * 8N = 32N. Therefore, the friction force = 0.4 * 32N = 12.8N.

There Are Five Books in a Stack,each with a Weight