1. The problem statement, all variables and given/known data Find magnitude of net upward force on a cube in terms of l, ρ (rho), g and h. then show that h = m/ρl2 A solid cube, mass m, side length l, is placed in a liquid of uniform density, ρ(rho), at a depth h0 below the surface of the liquid, which is open to the air. The upper and lower faces of the cube are horizontal. (this is from previous question https://www.physicsforums.com/threads/force-exerted-by-fluid.784711/) 2. Relevant equations pressure, p = ρ g h mass = ρ x volume of liquid displaced 3. The attempt at a solution Net force, Fn = (pbottom x area of cube face) - (ptop x area of cube face) p at top face = (pT) x ρliquid x h x g p at bottom face = (pB) x ρliquid x (h+l) x g so Fn = (ρgh + ρlg - ρgh) Fn = ρlg Net force - fine. Er! how do I show that h = m/ρl2 I know m = ρ x v . . .