A shelf PQ is fixed to a vertical wall at P and carries a book. A rigid bar XY keeps the shelf level, as shown. The shelf has weight $W_s$ and the book has weight $W_b$. The bar makes an angle $\theta$ with the shelf and applies a force $F$ to the shelf. The shelf is in equilibrium. What are the magnitudes of the horizontal and the vertical components of the force exerted by the wall on the shelf at P?
Physics 9702 · AS & A Level · Equilibrium of forces