unit a part 2 Flashcards
(21 cards)
What is viscosity?
Liquid’s internal resistance or friction that keeps it from flowing.
High viscosity indicates a thick liquid, while low viscosity indicates a thin liquid.
How does cohesive force relate to viscosity?
Cohesive force is stronger in liquids than in gases, indicating a more viscous liquid.
Stronger cohesive forces lead to higher viscosity.
What happens to the viscosity of a liquid as temperature increases?
Viscosity decreases as temperature increases.
This means the liquid flows faster at higher temperatures.
What is the formula for flow rate?
Flow Rate (FR) = Volume (ml) / time (s)
A slower flow rate indicates a higher viscosity.
What determines the density of an object?
Density is determined by the amount of mass occupying a certain volume.
Different substances have different densities due to their particle composition.
How is density calculated?
Density (D) = Mass (m) / Volume (v)
Units for liquids are g/mL or kg/L.
What is a hydrometer?
An instrument that measures the density of a liquid.
Each temperature bulb acts like a hydrometer.
What is buoyancy?
The tendency of an object to float when placed in a fluid.
Buoyant force is the upward force exerted by the fluid.
What occurs when the buoyant force is greater than the force of gravity?
The object will float.
This happens when the density of the liquid is greater than the density of the object.
What is the relationship between pressure and depth in a fluid?
The greater the depth, the greater the pressure.
This is due to the weight of the fluid above exerting pressure.
What does Pascal’s Law state?
When pressure is applied to a liquid in a container, it is transmitted equally and undiminished throughout the liquid.
This principle is fundamental in hydraulic systems.
What is compressibility?
The extent to which a substance (gases) can be compressed.
Gases are more compressible than liquids due to the space between particles.
What does a barometer measure?
The pressure of air in the atmosphere.
It is used to predict weather changes.
What happens when a diver ascends too quickly from depth?
Dissolved nitrogen bubbles out quickly, causing pain known as ‘the bends’.
This occurs due to rapid pressure decrease.
What is a hydraulic system?
A system that uses a liquid under pressure to transfer forces and move loads.
It operates according to Pascal’s Law.
What is the function of a pump?
A device that moves a fluid through or into something.
Common types include piston pumps and diaphragm pumps.
What is the effect of adding energy to particles in a substance?
It makes particles move faster and further apart, decreasing density.
This is often observed when heating a substance.
What is the difference between buoyant force and gravity?
Buoyant force is the upward force exerted by a fluid, while gravity pulls objects downward.
If buoyant force exceeds gravity, the object floats.
Fill in the blank: The formula for pressure is _______.
Pressure = Force / Area
Units for pressure are Pascals (Pa).
What is neutral buoyancy?
When the force of gravity is equal to the buoyant force.
Objects neither sink nor float in this state.
What happens to a submarine’s density to float?
It fills ballast tanks with air to decrease overall density below that of water.
To dive, it releases air and takes in water.
