What is the largest weight of the book he can hold vertically before it slips out of his fingers? The coefficient of static friction between his fingers and the book cover is 0.70.

The maximum mass of the book is 0.857 kg and maximum weight is 8.4 N.

Explanation:

Given:

Normal force acting on either side of the book (N) = 6 N

Coefficient of static friction (μ) = 0.70

Now, maximum frictional force that can act on the book is the addition of frictional force acting on both the faces of the book. So,

Maximum frictional force is given as:

So, the maximum weight of the book must be less than or equal to the maximum frictional force or else the book will fall between the fingers.

So, the maximum weight (gravitational force) of the book is 8.4 N.

Also, if the weight corresponds to the mass of the book then, we know that, mass is given as:

Therefore, the maximum mass of the book is 0.857 kg and maximum weight is 8.4 N.