Question

A manometer containing oil (rho=850kg/m3) is attached to a tank filled with air. If the oil-level difference between the two columns is 45cm and the atmospheric pressure is 98kPa, determine the absolute pressure of the air in the tank.

Answer 1

Answer:

• The absolute pressure (P) is 1.018 × 10⁵ Pa

Explanation:

To find the absolute pressure we need to find the pressure in the opposite arm, and that will be summed with the given atmospheric pressure.

Illustration is attached.

So,

⇒ P = Pₐ + ρgh

Substituting the values,

⇒ P = 98 kPa + (850 × 10 × 0.45)

⇒ P = 98000 + 3825

⇒ P = 101825

⇒ P = 1.018 × 10⁵ Pa

∴ The absolute pressure (P) is 1.018 × 10⁵ Pa.

Answer 2

Given :-

A  manometer containing oil (rho=850kg/m3) is attached to a tank filled with air. If the oil-level difference between the two columns is 45cm and the atmospheric pressure is 98kPa,

To Find :-

Absolute pressure

Solution :-

converting m into cm

100 cm = 1 m

45 cm = 45/100 = 0.45 m

At first finding pgh

pgh = (850 × 10 × 0.45)

pgh = 3825

Now

Pressure = Pₐ + pgh

Pressure = 98000 + 3825

Pressure = 101825 pascal