Unit C: Chapters, 7, 8, 9 Flashcards
What is a fluid?
A fluid is a material that doesn’t have a definite shape, is free to flow, and takes the shape of its container, like liquids and gases.
Name the points of the particle theory of matter.
The particle theory of matter states that:
- all matter is made of particle
- particles have small spaces between them
- particles are always moving
- particles move faster when heated
- particles attract each other
What are the types of flow, and what do they mean? What is an eddy? How can things be streamlined?
There are two types of flow:
-turbulent: irregular, chunky, mixed flow pattern
-laminar: calm, smooth, regular flow pattern.
An eddy is an area with slow-moving fluid, that happens behind an obstacle (rock). Things can be streamlined by the designers creating a smooth shape, so that the flow is calmer.
What is flow rate?
Flow rate is the measure of how quickly a fluid moves. I is measured in volume per unit time.
What is viscosity, and how does it relate to flow rate?
Viscosity is a measure of how easily a fluid’s particles can slide past each other. If a fluid’s viscosity is very high, the particles find it very hard to slide past each other, and the flow rate is slow.
What are cohesion, adhesion, and surface tension?
Cohesion is how strongly the particles of the same fluid attract each other. This affects its viscosity. Fluids with slow flow rates have a greater cohesion. Adhesion is a measure of how strongly particles of different substance attract each other. Surface tension is the attraction between the particles of the surface of a liquid.
What are fluid mechanics and dynamics? What are aero/hydrodynamics?
- Fluid mechanics is the study of how fluids move when they are staying still and moving.
- Fluid dynamics is a part of fluid mechanics, that deals with how fluids move.
- Aerodynamics is a part of fluid dynamics that deals with how gases move.
- Hydrodynamics is a part of fluid dynamics that deals with how liquids move.
What is weight?
Weight is the force of gravity acting on an object.
What is mass?
Mass is the amount of matter that makes up an object.
What is volume?
Volume is the amount of space an object takes up.
What is displacement?
Displacement is when an object takes the place of the fluid it is in.
What is density?
Density is a measure of the mass per unit volume of a substance. To calculate density, you do mass/volume.
What is buoyancy?
Buoyancy is the upward supportive force on an object in a fluid.
What is a swim bladder, and how does it help a fish with its buoyancy?
A swim bladder is a controllable chamber. It fills with oxygen, or more oxygen. No water enters the swim bladder. When more oxygen is in the swim bladder, the density of the fish is decreased, and it floats. When less oxygen is in the bladder, the density is increased, and the fish sinks.
What is a ballast tank?
A ballast tank is the submarine’s version of a swim bladder. It is a compartment, that fills with water, or takes out water in order to increase or decrease the density of the submarine.
