13 1 Fluid Pressure Pressure force distributed over

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 1000 N 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=n. Bhun. Naz 9 Gr. RXM: &imgrefurl=http: //www. cramster. com/answers-nov-10/physics/hydraulic-liftdesigning-hydraulic-lift-automobilegarage_1036604. aspx%3 Frec%3 D 0&docid=Ngg. Xi. Nge 0 HQo 6 M&imgurl=http: //s 3. amazonaws. com/answer -board-image/53 a 90 a 44 -d 431 -47 ca-94 ba-8772 efc 9500 a. jpeg&w=348&h=299&ei=Xk. IT 6 rb. Ao. Xqtgf. N 4 NTYBQ&zoom=1&iact=hc&vpx=245&vpy=296&dur=1377&hovh=208&hovw=242&tx=148 &ty=225&sig=105865835399718163433&page=5&tbnh=166&tbnw=193&start=76&ndsp=20&ved=0 CL 4 D EK 0 DMFc

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