Fluid Pressure

Flashcards on Fluid Pressure based on lecture notes.

Define fluid pressure.

A compressive normal force due to liquid per unit area. P = F/A

What are the units of pressure?

Pascal (Pa) = 1 N/m^2; 1 kPa = 10^3 Pa; 1 MPa = 10^6 Pa; 1 bar = 1000 millibar = 10^5 Pa

What causes fluid pressure?

A fluid in a container exerts a pressure because of its weight.

How does water pressure change with depth?

Water pressure rises when the depth of water increases. P = hρg, where h is depth, ρ is liquid mass density, and g is gravitational acceleration.

How does pressure act at a point in a fluid?

Pressure acts equally in all directions.

How does fluid pressure act at a wall or surface?

Fluid pressure acts perpendicular to the wall or surface.

State Pascal's Principle.

If pressure is applied to one part of a closed system, it is transmitted without loss in all directions.

What is the formula for absolute pressure in a liquid?

Pabs = Patm + Pgauge

Define gauge pressure.

Pgauge = hρg: Pressure due to liquid weight

What is the formula for Relative mass density (RD)?

RD = Specific gravity (SG) = Mass density of a fluid / mass density of water

What is Buoyancy?

When a solid body is submerged in a fluid, the fluid exerts an upward force on it. The size of the resulting upward force determines whether the body will float or sink.

What is Archimedes’ Principle?

The buoyant force upwards due to the fluid is equivalent to the weight of liquid the body displaces. F = (VρL) g