Water and mercury were poured into a glass. The thickness of the upper liquid layer is 4 cm

Water and mercury were poured into a glass. The thickness of the upper liquid layer is 4 cm, and the lower one is 5 cm. Determine the pressure on the bottom of the glass.

h1 = 4 centimeters = 0.04 meters – thickness of the upper liquid layer;

h2 = 5 centimeters = 0.05 meters – the thickness of the lower liquid layer;

g = 10 N / kg – acceleration of gravity;

ro1 = 1000 kg / m3 – water density;

ro2 = 13500 kg / m3 is the density of mercury.

It is required to determine the pressure at the bottom of the glass P (Pascal).

Since the density of mercury is greater than that of water, the mercury will be at the bottom and water at the top. Then, the water pressure at the bottom of the glass is:

P1 = ro1 * h1 * g = 1000 * 0.04 * 10 = 400 Pascal.

Mercury pressure:

P2 = ro2 * h2 * g = 13500 * 0.05 * 10 = 6750 Pascal.

The total pressure will be equal to:

P = P1 + P2 = 400 + 6750 = 7150 Pascal = 7.15 kPa.

Answer: the pressure on the bottom of the glass will be 7.15 kPa.