Question

An ice cube is placed in a glass of water. The cube is 2.0 cm on each side and has a density of 0.917 g/cm3. What is the magnitude of the buoyant force on the ice?

Answer 1

Since the cube floats, the buoyant force equals the force of gravity:

$$F_b=mg=\rho_i a^3g=0.07\text{ N}.$$