| A | B |
|---|
| fluid | any material that can flow and takes the shape of its container |
| pressure | the amount of force exerted on a given area;calculated by dividing force by area |
| pascal | the SI unit of pressure; Pa |
| atmospheric pressure | the pressure caused by the weight of the atmosphere |
| atmosphere | the layers of nitrogen, oxygen, and other gasses that surround the earth |
| 101 kPa | At sea level, the pressure of the atmosphere that is exerted on you |
| density | amount of matter in a given volume |
| buoyant force | the upward force that keeps an object immersed in or floating on a liquid |
| Archimedes' principle | the buoyant force on an object in a fluid is equal to the weight and volume of fluid that the object displaces |
| sinking | weight is greater than buoyant force |
| floating | weight is equal to buoyant force |
| buoying up | buoyant force is greater than weight |
| ballast tanks | help to increase the overall density of a submarine, allowing it to dive and surface |
| Bernoulli's principle | as the speed of a moving fluid increases, the fluid's pressure decreases |
| lift | the upward force in a fluid |
| thrust | the pushing or pulling force exerted by the the engine in an aircraft or rocket |
| drag | force parallel to the velocity of the flow;combined with thrust determines the speed of an aircraft |
| turbulence | an irregular or unpredictable flow of fluids |
| Pascal's Principle | a fluid in equillibrium in a vessel exerts an equal pressure in all directions |
| hydraulic devices | used to move or lift objects; work based on Pascal's principle |
