Buoyancy can provide restoring force for a solid floating object in a fluid. The force of buoyancy is pointed up and is equal to the weight of the displaced fluid. A compact object whose density is less than that of the fluid will float in the fluid. Consider a compact object of density p floating in a fluid of density p0. Let the object be shaped in the form of a rectangular box of area of cross-section A and height h. Let ho be the height from the bottom of the submerged part of the box when it is in equilibrium, i.e. when the weight of the box is balanced by the force of buoyancy as shown in Fig1.11 Area, A Figure 1.11: The oscillation of a floating object. (a) The box is partially submerged and in equilibrium. (b) The box is not in equiibrium since the force of bouyancy on the box is not equal to the weight of the box Using the equilibrium condition, the y-equation of motion of the box is: d2 dt2 Pog y. ph