Air Pressure mkm

7/29/2019 Air Pressure mkm

1/17

CHAPTER6

AIRPRESSURE

FORM 2SCIENCE
http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357http://www.google.com.my/url?sa=i&rct=j&q=using%20straw&source=images&cd=&cad=rja&docid=y8Xhn7s73QJNYM&tbnid=QJ8B6vwrpAYYWM:&ved=0CAUQjRw&url=http://lakeforestdentalarts.co/2012/01/using-drinking-straws-protect-teeth/&ei=P1b1UaqfMYn7rAfFooGYAQ&psig=AFQjCNEoD5F49S7Wo0f8eHQLX2z-aiZeLQ&ust=1375119277390357


2/17

6.1 AIR PRESSURE

The air around us presses on thesurfaces of the objects that are in it.

This is known as air pressure.

The kinetic theory of gases is used toexplain the existence of air pressure.


3/17

6.1 AIR PRESSURE

Kinetictheory of

gases

Air consists of alarge numbers ofparticles that are

moving freely in alldirections

The particlescollide with

surfaces theycome into contactwith and bounce

back

Each collisionexerts a force on

the surface

The forcesproduces a

pressure on thesurface


4/17

6.1 AIR PRESSURE

Experiment to show that air exerts pressure
http://2.bp.blogspot.com/-Pn3_0GHk5HQ/Ua_0DiPUJMI/AAAAAAAAAKQ/egRt-435g9Q/s1600/SAM_0149.JPGhttp://1.bp.blogspot.com/-X4uk1bIaa40/Ua_z_pv6yfI/AAAAAAAAAKA/1Av7jrSCLGk/s1600/SAM_0148.JPGhttp://3.bp.blogspot.com/-a_5cTrhPUrk/Ua_z-90Fo8I/AAAAAAAAAJ4/24c7uLtjGXA/s1600/SAM_0141.JPGhttp://1.bp.blogspot.com/-JicrLi6G090/Ua_z_0-h4_I/AAAAAAAAAKE/2bBieIjkLvU/s1600/SAM_0140.JPG


5/17

6.1 AIR PRESSURE

Volume

Temperature

Factors affecting air

pressure

Air pressure increases when

volume decreasesExplanation:

The air particles move about in a

smaller space. More particles hit

the walls of the container,

producing a larger force.

Therefore, a higher pressure acts

on the wall.

Air pressure increases when

temperature increases

Explanation:The air particles move faster.

More particles hit the walls of the

container with a greater force.

Therefore, the pressure

increases.


6/17

6.2 APPLICATION OF THE PRINCIPLE OF AIR PRESSURE

Applications of air pressure


7/17


Throwing leftovers into a sink can causeblockage in the drainage pipe. The

principle of air pressure is a simple and

effective way to remove the blockage.

Plunger is placedover the drainage

hole

Plunger is pusheddown. Air under

the rubber suckeris forced out

The air pressure isreduced


8/17


Pushing the plunger down reduces the air pressure


9/17


The plunger is pulledVolume of air underthe rubber sucker

increases

The air pressure isreduced

The higher external airpressure pushes theblockage which then

flows out with thewater


10/17


Pulling the plunger reduces the air pressure


11/17


Have you noticed that two holes arepunched at the top of a can of condensed

milk before the milk is poured out?

When the milk flows out of the can, the

pressure inside the can is reduced.

The higher air pressure outside

prevents the milk from coming out.


12/17


Can with one hole


13/17


The second hole allows air to enter thecan and fill up the empty space. The air

pressure in the can cause the milk to

flow out of the can.

Can with two holes


14/17


Gas tanks containing gas under high

pressure are used in various places such

as hospitals, factories and vehicles

workshops.

In a motor workshop, an electrical pumpis used to force air into a tank. The air

under high pressure is used to drive a

wrench to loosen tight screws or nuts. An aerosol can contains gas under high

pressure which acts as a propelling

agent to drive the liquid content out of


15/17


A wrench driven by air underhigh pressure

An aerosol can


16/17


Safety measures when using

gas under high pressure

Always place the tankupright

Do not dispose of

an aerosol can ina fire

Do not place the

tank near a heatsource


17/17

Documents

Air Pressure mkm