A U tube with both ends open to the atmosphere is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of 10   mm above the water level on the other side. Meanwhile, the water rises by 65   mm from its original level (see diagram). The density of the oil is____ ρ w = 1000   kg   m - 3

Step-by-step solution

∵ Pressure in a stationary liquid at the same level is the same everywhere. As both ends of the tube are open, the pressure on both free surfaces should be equal. h o i l   ρ o i l   g = h w a t e r     ρ w a t e r g   140 × ρ o i l = 130 × ρ w a t e r ρ o i l = 928   kg   m - 3 .