An Aluminum cube with size L is immersed in a box containing water and Mercury. Assuming that the cube is in equilibrium in the horizontal position, compute the height of the centre of mass of the cube with respect to the surface separating water and Mercury. density of water ρw = 1gcm−3
density of Mercury ρHg = 13.6gcm−3
density of Aluminum ρAl = 2.7gcm−3
L = 10cm.

B = (dm v1 + dw v2) g    where B = buoyant force and d the density

B = da ( v1 + v2) g     where v1 is volume of Hg displaced and v2 the water

(dm v1 + dw v2) = da ( v1 + v2)

v1 ( dm - da) = v2 ( da - dw)

v1 / v2 = (2.7 - 1) / (13.6 - 2.7) = .156

L1 = .156 L2    where L1 is length of side in Hg and L2 length of side in water

Since the center of mass is at L / 2  and L1 + L2 = L

L1 = .156 (L - L1)

L1 = .156 L / 1.156 = .135 L

L / 2 - .135 L = .365 L above the interface of the liquids

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid