There are nine books in a stack,each with a weight of 6 N.The coefficient of friction between all the books is 0.3 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 eight books off the bottom one?
A)1.80 N
B)14.4 N
C)48.0 N
D)16.2 N

Question

Quizplus · Accepted Answer

The force required to overcome friction and start sliding is given by $F = \mu N$, where $F$ is the force of friction, $\mu$ is the coefficient of friction, and $N$ is the normal force. Here, the normal force for the top eight books is $8 \times 6\,N = 48\,N$. With a coefficient of friction of 0.3, the force required is $F = 0.3 \times 48\,N = 14.4\,N$.

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