C8 Terms Flashcards
The study of how fluids flow and how forces and energy are transmitted through fluids
Fluid mechanics
The ratio of forces to the area
Pressure (P)
A pressure is exerted equally in all directions
Fluid pressure
The SI base unit of pressure
pascal (Pa)
Water pressure due to depth
hydrostatic pressure
A thick walled glass tube filled with liquid mercury and sealed on one end
mercury barameter
Contains a accordion like can filled with a low pressure gas
aneroid barometer
Fluid pressures is measured with?
gauge
An immersed object is lifted or buoyed up by a force equal to the weight of the fluid displacement. This is called the buoyant force
Archimedes’ principle
States that an immersed object is lifted up by a force equal to the weight of the fluid displaced
buoyant force
Comparing the density of an object to the density of water
specific gravity
Changes of pressure on a fluid are exerted equally throughout the fluid
Pascal’s principle
Hydraulic machine
They produce MA by magnifying a small force on a confined liquid to make a large force on the load
Hydraulics
Using a liquid to exert a force
Bernoulli’s principle
Pressure In a pipe is related to he waters height and it’s velocity
Venturi
A pressure meter that uses flow
Lift
An upward force p
Coanda effect
The diverting of the path of water flowing around a cylinder
Air foil
Any surface that is designed to deflect air or create a force as it moves though the air
Boyle’s law
The inverse relationship between the volume and pressure of a confined gas
Charles law
The volume of a fixed amount of gas changes in the same way as it’s absolute temperature
What property of fluids necessitated the development of fluid mechanics as an area of science separate from standard mechanics?
Because they have special physical properties such as lack of rigidity.
How is pressure calculated?
Pressure is calculated using the formula
F P=---- A
Where
• P is pressure in newtons per square meter
• F is the net force acting perpendicular to the surface in newtons
• A is the total surface area over which the force is applied
How does pressure change when each of its contributing factors is increased?
When force is increased the pressure rises. When the area is increased the pressure goes down.
How does pressure exerted by a solid object on a surface differ from pressure exerted within a liquid or a gas?
Liquids and gases exert pressure in all directions and a solid can only exert a pressure in one direction
What combination of SI units is the pascal equal to?
Newtons per square meter
What pressure unit is used in weather prediction?
The bar
What 2 factors affect the pressure in a fluid?
How does gravity affect each of these?
Depth and density
If there was no gravity the depth would not make a difference. Gravity pulls down on the particles and compresses the ones that are below the surface
What 2 aspects of a fluid do not affect fluid pressure?
Shape and volume
List the 3 kinds of buoyancy
Objects the float objects the sink, and objects that hover
Why is specific gravity useful?
It is useful as an identifying property of substances especially solutions and other mixtures
(T/F) If a mercury barometer were taken into a deep mine on a typical day, the mercury column would probably be taller than 760 mm.
False
What conditions must exist for pascal’s principle to be true?
The fluid must be totally contained
The fluid must be incompressible
What is one way to compute the ideal MA of a simple hydraulic machine?
Divide the area of the resistance piston be the area of the effort piston
What is the most important condition that must exist for a fluid to flow?
Pressure
(True or false) A manually operated hydraulic jack applies the Bernoulli principle to amplify effort to do work.
False
Research in gases lead to the acceptance of what principal theory of science.
The theory of particle matter
What three factors contribute to gas pressure.
Temperature, the number of gas molecules in a volume of gas, and the number of collisions per second
If the volume of a confined gas triples what happens to the gas’s pressure?
It will be one third of the original pressure
When a confined gas experiences a temperature change which of the three factors from the question above could change the pressure of the gas?
The speed of the molecules
(True or false) An oxygen molecule has eight times as much mass as a hydrogen one.
False
