Monday, October 24, 2011

5.6 Demo - squirting water column

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·         The bottom hole squirts water the furthest

·         Because the water at the bottom has the greatest pressure

·         Because in the formula ∆p = h × ρ × g, ρ is constant, g is constant and h is large

·         So ∆p = large

5.6

·         5.6 recall and use the relationship for pressure difference:

 

        pressure difference = height × density × g

                               ∆p = h × ρ × g

 

 

∆p = pressure of the fluid (N/m2 or Pa)

h = height of the fluid (m)

ρ = density of the fluid (kg/m3)

g = gravitational field strength (N/kg)

5.5 Demo 1 - Magdeburg Hemispheres

Magdeburg Hemispheres

 

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·         And here are the horses I was talking about!

5.5

·         5.5 understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions

 

 

<<Pressure Underwater.wmv>>

 

 

5.4 Pressure Questions

·         PFY p.91, Q.3 and 7.

image006.emz Download this file

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5.4

Pressure Formula.ppt Download this file

·         5.4 recall and use the relationship between pressure, force and area:

        pressure = force / area

                  p = F / A

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animation - why a drawing pin works.swf Download this file

 

·         Your finger pushes on the pin and the pin pushes back on your finger

·         N3L tells us that all these two forces are equal in size

·         The pin pushes on the wall and the wall pushes back on the pin

·         N3L tells us that all these two forces are also equal in size

·         If the surface area is large then the force is spread over a large area and the pressure is low

·         If the surface area is small then the force is spread over a small area and the pressure is high

·         You would like the pressure on your finger to be low and the pressure on the wall to be high

·         The other way round is painful!

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Unit_5_Keywords_and_Mixed_Defi.docx Download this file