13.1 Fluid Pressure - Ms. Hill's Website


13.1 Fluid Pressure

Pressure- force distributed over an area;

Pressure= F/area

Pressure in Fluids

Water pressure increases as depth increases

The pressure of any fluid at specific depth is constant and equal pressure in every direction

Fluid pressure determined by type of fluid and depth

(volume or weight does not affect pressure!)

Air Pressure in Atmosphere

Air pressure decreases as altitude increases

Atmosphere exerting 1000N of pressure on you!

13.2 Forces & Pressure in Fluids

Pascal’s Principle: a change in pressure at any point in a fluid is transmitted equally and unchanged in all directions through fluid

Hydraulic Systems

Increases output force due to constant fluid pressure exerted over larger area of the output piston http://www.google.com/imgres?q=hydraulic+lift+system+piston&hl=en&biw=1024&bih=692&tbm=isch& tbnid=nBhunNaz9GrRXM:&imgrefurl=http://www.cramster.com/answers-nov-10/physics/hydraulic-liftdesigning-hydraulic-lift-automobilegarage_1036604.aspx%3Frec%3D0&docid=NggXiNge0HQo6M&imgurl=http://s3.amazonaws.com/answer





13.2 Forces & Pressure in Fluids

Bernoulli’s Principle: as the speed of fluid increases the pressure within the fluid decreases

Airplane wings/ lift

Air over top of wing is faster then air passing under

Pressure difference causes lift= keep flying

Spray bottles

Pressure difference from chamber and tube forces solution up tube and mixes with water moving out bottle

13.3 Buoyancy

Buoyancy results in the apparent loss of weight of an object in a fluid.

Buoyant force- upward force acting against gravity

Archimedes’ Principle-buoyant force of an object = weight of the fluid displaced by the object

Density and buoyancy- object less dense than liquid floats; object is more dense than liquid it sinks; suspended if object has same density as liquid

13.3 Buoyancy