Fluids Part 2 Flashcards
(18 cards)
Buoyancy
The tendency of a object in a fluid to rise or sink due to the density differences with its surroundings
Density
Amount of mass contained in a given volume
Flow rate
Measure of the speed at which fluid flows from one point to another, this is determined by measuring the amount of fluid that flows past a given point in a given time
Pressure
Amount of force applied to a given area
Compressibility
Property of being able to be compressed or made more compact
Viscosity
Resistance of a fluid’s ability to flow
Displacement
Occurs when something takes the place of something else
Pascal’s Law
Law that states that when force is applied to an enclosed fluid, increase in pressure is transmitted equally to all parts of the fluid
Buoyant force
The upward force that a fluid exerts on an object
Archemides Principal
The upward, buoyant force that is exerted on a body immersed in a fluid is equal to the weight of the fluid displaced by the object
How do you calculate the density of a fluid?
Mass/volume
How does temperature affect the density of a fluid?
Temperature increases, the density of a fluid decreases.
Heating a substance causes molecules to speed up and plead slightly farther apart, occupying a larger volume that results in a decrease in density.
What is the relationship between flow rate and viscosity?
When a fluid has a higher density it has a lower flow rate but when a fluid has a lower density it will have a higher flow rate so they measure the opposite
What factors affect flow or viscosity?
Adhesion, temperature, cohesion, friction, particle size and concentration
How is a cruise ship able to float despite its mass?
The mass of the water it displaces is greater than its mass
What is negative, neutral and positive buoyancy? Give examples for each.
Negative buoyancy - substances with a density of more than 1 sink in water (coins, rocks, brick)
Neutral buoyancy - substances that neither sink nor float (submarines, fish, divers)
Positive buoyancy- substances with a density of less than 1 float in the water (wood, ball, boat)
Differences between pneumatic and hydraulic devices
Pneumatic devices - use air pressure to do work, works quickly, clean (good for food and clothing, lighter work, louder, cheaper to repair, not affected by temperature.
Hydraulic devices- use liquid pressure (normally oil) to do work, works slower, not as clean, force multiplier allows it to complete heavy work, quieter, more costly
A can with three side holes
