fluids notes

• liquids are more dense than gas
• liquids have a definite volume independent of the size and shape of container
• the forces are not strong enough to keep the mlecules in a fixed position
• pressure is force / area with a unit of Pa
• when you stand on one foot or two feet the force is the same
• pressure is depth dependent and not volume dependent
• pressure acts equaly in all directions
• the shape of a container does not matter because pressure will be the same at all depths
• water pressure provided by a water tower is greater of the tower is taller
• water pressure is perpendicular to the surfaces of a container so liquid spurts at right angles
• buoyancy equals the weight of water displaced
• displacement rule is a submerged object will always displace a volume equal to its own volume
• buoyant force is the net upward force that a fluid exerts on an immersed object
• an object will sink when the weight of submerged object is greater than the buoyant force
• archimedes' principle is buoyant force equals the weight of an objects displaced
• the weight of an object in air is its actual weight
• the weight when an objects is completely submerged in water is the apparent weight
• when a fish makes itself less dense the buoyant force on it increases
• an object more dense will sink
• principle of flotation is a floating object displaces a weight of fluid equal to its own weight
• pascals principle is a change in pressure at any point will be transmitted to all points
• the contractive tendency of the surface is surface tension
• a sphere has the least surface area for a given volume
• surface tension is caused by molecular attractions
• the type of liquid, what is mixed, and temperature can all effect surface tension
• water has a greater surface tension than oil
• soapy water has a lower surface tension than water without soap
• cold water has a higher surface tension than cold water
• the rise of a liquid in a fine hollow tube is a capillarity
• surface tension causes the film on the surface to contract
• when the force of the surface tension balances out the weight of the liquid the liquid stops rising
• the height of the rise depends on the weight of the tube and the narrowness of the tube