1.8 Pressure Flashcards
Liquid pressure formula / The pressure due to a column of liquid eqn:
p = hdg
△p = pg△h
Where:
Δp = change in pressure in pascals (Pa)
Where 1 Pa = 1 N/m2
ρ = density of the liquid in kilograms per metre cubed (kg/m3)
g = gravitational field strength on Earth in newtons per kilogram (N/kg)
Δh = change in height of the column in metres (m)
Pressure is defined as
The concentration of a force or the force per unit area
pressure at the surface of a fluid can be calculated using the equation:
Pressure = force ÷ area
Pressure is measured in the units …
Pascals (Pa)
The area should always be the…
The area should always be the cross-sectional area of the object
This means the area where the force is at right angles to it
If a force is spread over a large area it will result in a ____ pressure
If it is spread over a small area it will result in a _____ pressure
Small pressure
Small area => large pressure
What is a fluid?
either a liquid or a gas
When an object is immersed in a fluid, the fluid will exert pressure, squeezing the object
This pressure is exerted ___< across the whole surface of the fluid and in all directions
Evenly
The pressure exerted on objects in fluids creates forces against surfaces
What angle do these forces act?
These forces act at 90 degrees (at right angles) to the surface
The pressure of a fluid on an object will increase with:
Depth within the fluid
Increased density of the fluid
pressure is more accurately
the difference in pressure at different depths h in a liquid, since the pressure changes with the depth
