• 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!

• 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
-board-image/53a90a44-d431-47ca-94ba-8772efc9500a.jpeg&w=348&h=299&ei=XkI-
T6rbAoXqtgfN4NTYBQ&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=0CL4D
EK0DMFc

• 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

• 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