Question

find the minimum force required to keep a book up. What is the maximum allowable force, as a function of θ and μ? Is there a special angle that arises? Given μ, make a rough plot of the allowed values of F for −π/2 < θ < π/2.

Answer 1

(a) Find the minimum force required to keep a book up.

F_min = N = mg sin $\theta$

(b) What is the maximum allowable force, as a function of $\theta$ and _$\mu$?

F = f_s,max

F_max = _$\mu$s F_N

F_max = _$\mu$s mg cos $\theta$

(c) Is there a special angle that arises?

No