Physics Gas Pressure & Atmospheric Pressure
-
Upload
angelyn-mendy -
Category
Science
-
view
280 -
download
10
Transcript of Physics Gas Pressure & Atmospheric Pressure
![Page 1: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/1.jpg)
CHAPTER 3.3 GAS PRESSURE
![Page 2: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/2.jpg)
GAS PRESSURE
Force per unit area exerted by the gas
particles as they collide with walls of the
container.
![Page 3: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/3.jpg)
Kinetic Theory of Gases
• Discrete. • Moves freely in random motion.
![Page 4: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/4.jpg)
Kinetic Theory of Gases
• Kinetic energy increases with the temperature.
![Page 5: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/5.jpg)
Kinetic Theory of Gases
• Collisions with each other and the walls of the container are elastic.
• Forces of attraction
NEGLIGIBLE.
![Page 6: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/6.jpg)
ATMOSPHERIC
PRESSURE
It is a thick layer of air that surrounds the earth.
It occurs when gas molecules collides to each other in the atmosphere and an object.
It acts in all direction.
The value of atmospheric pressure is about 1.0 x 105 N m-2 or 1.0 x 105 Pa.
![Page 7: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/7.jpg)
![Page 8: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/8.jpg)
![Page 9: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/9.jpg)
![Page 10: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/10.jpg)
INSTRUMENTS FOR MEASURING GAS PRESSURE
U-tube manometer
Bourdon gauge
![Page 11: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/11.jpg)
U-TUBE MANOMETERThe gas whose pressure is to be measured is connected directly to one side of the U-tube.The pressure of the gas is equal to the sum of atmospheric pressure and the pressure due to the difference in the height of the liquid in the manometer.
![Page 12: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/12.jpg)
BOURDON GAUGECommonly used in school laboratories, air
conditioner service shops, hospitals and factories.
When a Bourdon gauge is attached to a gas cylinder, gas flows from the cylinder into the flattened curved tube in the gauge.
The pressure of the gas causes the curved tube to straighten out.
Through a lever and a gear system, the pointer rotates to measure the pressure of the gas.
![Page 13: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/13.jpg)
INSTRUMENTS FOR MEASURING ATMOSPHERIC PRESSURE
oMercury barometer
oFortin barometer
oAneroid barometer
![Page 14: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/14.jpg)
MERCURY BAROMETERMade by inverting a long glass tube filled with
mercury.
Due to the inversion, a vacuum is created at the base of the tube and a column of mercury is supported by the atmospheric pressure.
The units for the measurement of atmospheric pressure can be in terms of centimeters of mercury (cm Hg) or Pascal (Pa). Another unit of pressure is torr, where 1 torr is equal to 1 mm Hg.
![Page 15: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/15.jpg)
FORTIN BAROMETER• Essentially modified from a simple mercury
barometer.
• The Fortin barometer has a metal scale with a vernier attached and a mirror behind the top of the mercury column to avoid parallax error when taking readings.
• With these features, the Fortin barometer measures the atmospheric pressure more accurately than the simple mercury barometer.
![Page 16: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/16.jpg)
ANEROID BAROMETER More convenient form of barometer because it
does not use liquid and can be as small as a wristwatch.
Inside an aneroid barometer there is a partially evacuate metal case made of thin and flexible alloy.
A change of atmospheric pressure will cause the centre of the metal case to move in or out. This movement is magnified by a system of levers.
A chain attached to the last lever rotates the pointer to show the atmospheric pressure measured.
![Page 17: Physics Gas Pressure & Atmospheric Pressure](https://reader033.fdocuments.in/reader033/viewer/2022051202/58a4c4f51a28ab480e8b4c2f/html5/thumbnails/17.jpg)
THE END !
THANK YOU FOR LENDING US YOUR EARS!!!