strategic intervention reference card materials on physicst909 tsf

7/27/2019 Strategic Intervention ReferEnce Card Materials on Physicst909 Tsf

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Strategic Intervention ReferEnce

Card Materials on PhysicstPrepared by;

MARJORIE Q.REFORMA

IV-TANIGUESEPTEMBER 5,2012


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INTRODUCTION

Pressure

Pressure is defined as force per unit area. It isusually more convenient to use pressure ratherthan force to describe the influences upon fluidbehavior. The standard unit for pressure is thePascal, which is a Newton per square meter.

For an object sitting on a surface, the forcepressing on the surface is the weight of theobject, but in different orientations it might havea different area in contact with the surface andtherefore exert a different pressure.
http://hyperphysics.phy-astr.gsu.edu/hbase/mass.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/mass.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/mass.html


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Guide card

Hello welcome to the world in pressure is the amount of force

exerted on agiven area


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Pressure calculation.

There are many physical situations where pressure is the most important variable. If you are peeling an

apple, then pressure is the key variable: if the knife is sharp, then the area of contact is small and you can

peel with less force exerted on the blade. If you must get an injection, then pressure is the most important

variable in getting the needle through your skin: it is better to have a sharp needle than a dull one since

the smaller area of contact implies that less force is required to push the needle through the skin.

When you deal with the pressure of a liquid at rest, the medium is treated as a continuous distribution of

matter. But when you deal with a gas pressure, it must be approached as an average pressure from

molecular collisions with the walls. Pressure in a fluid can be seen to be a measure ofenergy per unit volume by means of the definition

ofwork. This energy is related to other forms of fluid energy by theBernoulli equation.
http://hyperphysics.phy-astr.gsu.edu/hbase/prcal.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pflu.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kinthe.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/work2.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/work2.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kinthe.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pflu.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/prcal.html


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Pressure as Energy Density

Pressure in a fluid may be considered to be a measure ofenergy perunit volume or energy density. For a force exerted on a fluid, this can

be seen from the definition of pressure:

The most obvious application is to the hydrostatic pressure of a fluid,

where pressure can be used as energy density alongside kinetic energy

density andpotential energy density in the Bernoulli equation.

The other side of the coin is that energy densities from other causes

can be conveniently expressed as an effective "pressure". For example,

the energy density of solvent molecules which leads to osmosis is

expressed as osmotic pressure. The energy density which keeps a starfrom collapsing is expressed as radiation pressure.
http://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/conser.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pflu.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/diffus.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/astro/transp.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/astro/transp.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/diffus.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pflu.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/conser.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/press.html


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Fluid Kinetic Energy

The kinetic energy of a moving fluid is more useful in applications like the Bernoulli equation when

it is expressed as kinetic energy per unit volume

When the kinetic energy is that of fluid under conditions oflaminar flow through a tube, one must

take into account the velocity profile to evaluate the kinetic energy. Across the cross-section of

flow, the kinetic energy must be calculated using the average of the velocity squared , which is not

the same as squaring the average velocity. Expressed in terms of the maximum velocity vm at the

center of the flow, the kinetic energy is
http://hyperphysics.phy-astr.gsu.edu/hbase/ke.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pfric.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pfric.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pfric.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pfric.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/pber.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/ke.html


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ACIVITY NO.1

Warning all grownups: get your sense of humor readyfor this science experiment, which demonstratesfundamental physics of air pressure. You can do this ina lab, of course, or with technical worksheets, but we

love this goofy magic trick with a kid and agrownupand an audience, too, if you dare.

What You Need:

2 plastic drink bottles, 1-2 liters in size, clean and dry

Latex balloons

Pin or tack


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ACIVITY NO.2


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ACTIVTY NO.3 Pressure Activityscaffolding activityIntroduction:Introduction:Though you may not realize it, the air has weight. All the airmolecules in the atmosphere exert a force, or pressure, on ourbodies. Atmospheric pressure is the force exerted by the weight of

the air above an object or surface. Variations in pressure generatewinds, which play a significant role in day to day weatherconditions. The purpose of this activity is to introducecharacteristics of pressure, high and low pressure centers, and abrief analysis of an idealized pressure field. Key words throughoutthis activity link directly to helper resources that provide useful

information for answering the questions.


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Characteristics of Pressure:1) What are the different units of pressure? Which unit is used most

by meteorologists?

2) Circle the correct response in the following sentence: Pressure(increases / decreases) with height. Please explain why pressurechanges this way with height.

High and Low Pressure Centers:3) Draw the symbol that represents a high pressure center on aweather map. Do the same for a low pressure center.

4) Pictured below are two imaginary columns of air molecules

exerting pressure on the surfaces below them. The left columncontains fewer air molecules than the right column.
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_units.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_units.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_units.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_height.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_height.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_height.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_units.rxml?hret=/guides/crclm/act/prs.rxml


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Which column is more representative of the atmosphere above a highpressure center? Which one is more likely to be found over a low

pressure? Using the correct symbols for labeling high and low pressure

centers (see question #3), mark your answers beneath the appropriate

columns in the diagram above. You may label the diagram in one of two

ways; 1) by printing out a copy of this activity and marking your answers

directly onto the printout or 2) by saving the image into your favoritegraphics software and modifying the image using that graphics package.
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxml


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Analysis of a Pressure Field:

5) The diagram below is an idealized pressure field resembling those commonly found on

surface weather maps. The numbers along each contour indicate the pressure value in

millibars for that particular contour. Use the diagram below to answer the following

questions.

What are the green contours? What do they represent?
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/isobars.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/isobars.rxml?hret=/guides/crclm/act/prs.rxml


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Label the diagram above to indicate the positions ofthe high and low pressure centers. Please use the correct symbols (seequestion #3). You may label the diagram in one of two ways; 1) by printingout a copy of this activity and marking your answers directly onto theprintout or 2) by saving the image into your favorite graphics software andmodifying the image using that graphics package.

Draw an arrow (on the diagram above) to indicate the direction in whichthe pressure gradient force is pointing.

Examine the Current Pressure Field:6) Using what you learned in questions 1-5, open the following map andcreate the latest map ofisobars. On this map, mark the positions

ofhigh and low pressure centers (using the correct symbols). You may label your image in one of two ways; 1) by printing out a copy of

the image and marking your answers directly onto the printout or 2) bysaving the image into your favorite graphics software and modifying theimage using that graphics package.
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_gradient.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_gradient.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/isobars.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/isobars.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/isobars.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/pressure_gradient.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/low_pressure_center.rxml?hret=/guides/crclm/act/prs.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/anticyclone.rxml?hret=/guides/crclm/act/prs.rxml


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ASSESMENT TEST 1.What is the pressure of the cylinder?


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What is the pressure of spring?


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Pressure=force/area


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ENRICHSENT CARD


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REFERENCE CARD


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ANSWER CARD

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