Two liquids, 1 and 2, are in equilibrium in a U-tube that is open at both ends, as in the drawing. The liquids do not mix, and liquid 1 rests on top of liquid 2. How is the density ρ1 of liquid 1 related to the density ρ2 of liquid 2?
(a) ρ1 is equal to ρ2 because the liquids are in equilibrium.
(b) ρ1 is greater than ρ2.
(c) ρ1 is less than ρ2.
(d) There is not enough information to tell which liquid has the greater density.