A book is sitting at the leftmost edge of a 10 m long wooden plank. Someone slowly lifts the wooden plank, creating an angle ? with respect to the surface, as shown below. The coefficients of friction between the book and the plank are s = 0.5 and k = 0.3.

Book {mows as) 10 m LL = 0.5 S LL = 0.3 D