Archimedes' Principle states that when an object is immersed in a fluid, the buoyant force is equal to the weight of the fluid displaced by object. The weight of an object is equal to its mass times the acceleration due to gravity. Therefore, the weight of the fluid displaced is equal to the volume of the fluid displaced times the density of the fluid times the acceleration due to gravity.

Weight (N, newtons) - mass (kg) x g. At sea level, g = 9.81 m/s2.

A cube of lead (? = 11.3 x 103 kg/m3) is placed in a pool mercury (? = 13.6 x 103 kg/m3). The cube of lead is 3.60 x 102 cm on a side. Calculate the percentage of the cube that is above the pool of mercury.