Kerosene is poured in the right knee of communicating vessels, in the left knee, the height of kerosene is 20 cm

Kerosene is poured in the right knee of communicating vessels, in the left knee, the height of kerosene is 20 cm, determine how much the level of kerosene in the right knee is higher than the upper water level.

To estimate the difference in the height of the levels of kerosene and water, we use the formula: Δh = hker – hv = hker – ρker * hker / ρv = hker * (1 – ρker / ρv).

Constants and variables: hker – the height of the kerosene level in the right knee (hker = 20 cm); ρker is the density of kerosene (we take ρker = 800 kg / m3); ρw is the density of water (we take ρw = 1000 kg / m3).

Calculation: Δh = hker * (1 – ρker / ρv) = 20 * (1 – 800/1000) = 4 cm.

Answer: The kerosene level is 4 cm higher.