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Ch.13 Fluid Pressure
fluid pressure
Question | Answer |
---|---|
3 main state of matter | solid liquid gas |
Anything that flows and takes the shape of its container | fluid |
Fluids can be what 2 states of matter | liquid or gas |
The ratio of mass to volume in a substance | density |
Equation for density | D = m/V |
Si units for density | g/cm3 or g/mL |
Si units for mass | g or kg |
SI units for volume | L or mL or cm3 or m3 |
The amount of matter in something | mass |
The space something takes up | volume |
Measured on a balance | mass |
Measured in a graduated cylinder | volume |
A push or pull on something | Force |
SI unit for force | Newton |
Force is measured with what? | spring scale |
What is pressure | the force acting over a certain area |
Equation for pressure | P = F/A pressure = force/area |
What is the SI unit for pressure | N/m2 or Pa (pascal) |
In a fluid, pressure _________ as depth increases | increases |
The pressure at any specific depth is __________. | constant or the same |
In any fluid what 2 things does pressure depend on | depth and density |
______ ____________ is the fluid pressure of the atmosphere stacked on top of us. | air pressure or atmospheric pressure |
As altitude increases (going up in the mountains or up in a plane), air pressure __________________. | decreases |
States that a change in pressure at any point in a fluid is transmitted equally throughout the fluid | Pascal's Principle |
What is a hydraulic system | A device that uses pressurized fluid acting on connected pistons of two different sizes to change a force |
How does a hydraulic system work | as pressure is added to a small piston it is also increased in the larger piston. But there is a bigger area and thus a bigger force at the larger piston |
State Bernoulli's principle. | as the speed of a fluid increases, the pressure decreases or speed and pressure are inversely proportional in a fluid |
As the speed of a fluid _____________, pressure increases | decreases |
What happens to windows and roofs in a tornado and why? | The blow out or up because speed is greater and pressure is less outside |
How does a wing produce lift just by its shape cutting through the air? | Air on the top side goes faster and pressure on top decreases. More pressure under the wind creates a pressure difference that causes lift |
Name the forces on an airplane | lift, drag, weight, thrust |
This is the movement of a planes nose up or down | pitch |
This is the movement of a planes nose side to side | yaw |
This is the movement of a plane where the wings go up or down as it rotates around the center axis of the plane | roll |
What control surface makes a plane pitch? | elevators on the tail |
What control surface makes a plane roll? | ailerons on the wing |
What control surface makes a plane yaw? | rudder on the tail |
This is the ability of a fluid to exert an upward force on an object placed in it | buoyancy |
Another name for floating | positive buoyancy |
Another name for sinking | negative buoyancy |
What is it called when something stays exactly submerged where you place it in a fluid | neutral buoyancy or "flinking" |
This is the upward force acting on an object in a fluid | buoyant force |
What produces buoyant force on an object | The pressure is greater at the bottom of an object than the top (Remember the golf ball in water picture!) |
Whether something floats or sinks depends on ___ and ___. | Density and Buoyancy |
State Archimedes' principle | The upward force acting on an object in a fluid is equal to the weight of the fluid displaced by the object |
How does a submarine dive | it takes water into its ballast tanks making it heaver than the buoyant force from the weight of the water it displaces |
Why does a piece of clay sink, but in a boat shape it floats? | in the boat shape it displaces more than its weight in water |