| |
|
|
| |
| |
Atmospheric pressure |
|
| |
Pressure due to the weight of the layer of air acting on the surface of the Earth.
|
|
| |
|
|
|
|
| |
|
Instruments to measure atmospheric pressure
|
- Fortin barometer
- Mercury barometer
- Aneroid barometer
|
| |
|
Applications of atmospheric pressure
|
- Drinking straw
- When straw is sucked, the air velocity in straw is high
- The air pressure in the straw is lower than atmospheric pressure
- Air is pushed up into a straw by atmospheric pressure
- Rubber sucker
- When the rubber is pressed, the air is removed
- There is low pressure inside rubber sucker (partial vacuum)
- Atmospheric pressure is higher than pressure inside rubber
- Rubber sucker sticks on surface
- Siphon
- Atmospheric pressure is higher than the pressure in the siphone
- The atmospheric pressure acting on liquid push the liquid down to a lower container
- Syringes
- When the piston is pulled, the pressure in the syringe decreases
- The pressure in the syringe is lower than atmospheric pressure
- The atmospheric pressure at the surface force water into the syringe.
- Vacuum cleaner
- Vacuum fan removes air from space inside dust bag
- The pressure in the dust bag is lower than atmospheric pressure
- Outside air is sucked into the dust bag together with dusts
|
| |
| |