Question

A student presses a book between his hands, as the drawing indicates. The forces that he exerts on the front and back covers of the book are perpendicular to the book and are horizontal. The book weighs 32.9 N. The coefficient of static friction between his hands and the book is 0.416. To keep the book from falling, what is the magnitude of the minimum pressing force that each hand must exert?

Answer 1

Answer: 39.5 N

Explanation:

2 x force x static friction coefficient = weight  (weight=2μsF)

force = ?

static friction coefficient = 0.416

weight = 32.9N

substituting the values above into the equation we get

2 x F x 0.416 = 32.9

F = 32.9 / (2 x 0.416)

F = 39.5N