A bookshelf is 2m long, with supports at its end (p and q). A book weighing 10N is placed in the middle of the shelf. what are the upward forces?

If the book is placed in the middle, the forces acting on p and q is 5N. If the book is moved 50 cm from q, the forces at p and q can be solved by doing a moment balance

With p as the pivot;

Fq (2 m) = 10 N (0.5 m)

Fq = 2.5 N

Fp = 10 N - 2.5 N = 7.5 N