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?????? G.5 ??? ??? ???? ???? physics

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Atmospheric pressure is the force per unit area exerted by the weight of air above a surface. It is closely approximated by the hydrostatic pressure from the weight of the overlying air. Areas with less atmospheric mass above them have lower pressure, while areas with more atmospheric mass have higher pressure. Pressure also decreases with increasing elevation as there is less overlying atmospheric mass. Standard atmospheric pressure is used as a reference point and is defined as 1.01325 bar or 101325 Pa at sea level and 0¡ãC. Any instrument that measures air pressure is called a barometer. Torricelli first measured atmospheric pressure using a mercury-filled tube in 1643.

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?????? G.5 ??? ??? ???? ???? physics
?????? G.5 ??? ??? ???? ???? physics
Vocabulary atmospheric pressure(n.)
Vocabulary experiment (n.)
Vocabulary measurement (n.)
Vocabulary barometer(n.)
Vocabulary circumstance(n.)
Vocabulary mass(n.)
Vocabulary elevation (n.)
Vocabulary overlying (v.)
Vocabulary mercury (n.)
Structure Passive Voice In passive sentences, the subject of the verb is not the person or thing (the ¡°agent¡±) doing the action. Structure Subject + auxiliary verb (be) + main verb (past participle) + (by) +¡­
Structure Use of the Passive Voice We use the passive when: ? We want to make the active object more important. ? We do not know the active subject.
Structure ? Look at these examples: auxiliary verb subject (be) 1. Atmospheric pressure is closely approximated by the hydrostatic pressure. main verb (past participle)
Structure ? Look at these examples: auxiliary verb subject (be) ? 2. Standard Atmospheric Pressure is used as a reference for gas densities and volumes. main verb (past participle)
Structure Look at these examples: subject auxiliary verb (be) 3. The Standard Atmospheric Pressure is defined at sea-level. main verb (past participle)
Structure Look at these examples: subject 4. Any instrument that measures air pressure is called a barometer. auxiliary verb (be) main verb (past participle)
Text 3 Atmospheric pressure Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that pressure decreases with increasing elevation.
Standard Atmospheric Pressure ? Standard Atmospheric Pressure (atm) is used as a reference for gas densities and volumes. The Standard Atmospheric Pressure is defined at sea-level at 273oK (0oC) and is 1.01325 bar or 101325 Pa (absolute). The temperature of 293oK (20oC) is also used.
Measuring Atmospheric Pressure ? Any instrument that measures air pressure is called a barometer. The first measurement of atmospheric pressure began with a simple experiment performed by Evangelista Torricelli in 1643. In his experiment, Torricelli immersed a tube, sealed at one end, into a container of mercury. Atmospheric pressure then forced the mercury up into the tube to a level that was considerably higher than the mercury in the container. Torricelli noticed that height of the mercury varied with changes in outside weather conditions. The most common type of barometer used in homes is the aneroid barometer
Figure 1: Diagram showing the construction of Torricelli's barometer.
Figure 2: Aneroid barometer.
Speaking Writing
Speaking Experiment Role-play ? Situation: You are in the science experiment contest. You have to present your project, remember to give the following science process ? 1. Observation 2. Hypothesis Forming 3. Data Gathering 4. Performing Experiement to test you hypothesis 5. Results Recording ? The rest of other groups are the committee and try to find out the faults by using some questions. ? Make a group of 5 ? I will give you 10 minutes
Writing Create your own experiment about ¡°Atmospheric Pressure¡± by using the following materials: ? Paper ? Glass ? Water Then write on the paper and present in front of class.
Atmospheric Pressure.

More Related Content

?????? G.5 ??? ??? ???? ???? physics

  • 12. Structure Passive Voice In passive sentences, the subject of the verb is not the person or thing (the ¡°agent¡±) doing the action. Structure Subject + auxiliary verb (be) + main verb (past participle) + (by) +¡­
  • 13. Structure Use of the Passive Voice We use the passive when: ? We want to make the active object more important. ? We do not know the active subject.
  • 14. Structure ? Look at these examples: auxiliary verb subject (be) 1. Atmospheric pressure is closely approximated by the hydrostatic pressure. main verb (past participle)
  • 15. Structure ? Look at these examples: auxiliary verb subject (be) ? 2. Standard Atmospheric Pressure is used as a reference for gas densities and volumes. main verb (past participle)
  • 16. Structure Look at these examples: subject auxiliary verb (be) 3. The Standard Atmospheric Pressure is defined at sea-level. main verb (past participle)
  • 17. Structure Look at these examples: subject 4. Any instrument that measures air pressure is called a barometer. auxiliary verb (be) main verb (past participle)
  • 18. Text 3 Atmospheric pressure Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that pressure decreases with increasing elevation.
  • 19. Standard Atmospheric Pressure ? Standard Atmospheric Pressure (atm) is used as a reference for gas densities and volumes. The Standard Atmospheric Pressure is defined at sea-level at 273oK (0oC) and is 1.01325 bar or 101325 Pa (absolute). The temperature of 293oK (20oC) is also used.
  • 20. Measuring Atmospheric Pressure ? Any instrument that measures air pressure is called a barometer. The first measurement of atmospheric pressure began with a simple experiment performed by Evangelista Torricelli in 1643. In his experiment, Torricelli immersed a tube, sealed at one end, into a container of mercury. Atmospheric pressure then forced the mercury up into the tube to a level that was considerably higher than the mercury in the container. Torricelli noticed that height of the mercury varied with changes in outside weather conditions. The most common type of barometer used in homes is the aneroid barometer
  • 21. Figure 1: Diagram showing the construction of Torricelli's barometer.
  • 22. Figure 2: Aneroid barometer.
  • 24. Speaking Experiment Role-play ? Situation: You are in the science experiment contest. You have to present your project, remember to give the following science process ? 1. Observation 2. Hypothesis Forming 3. Data Gathering 4. Performing Experiement to test you hypothesis 5. Results Recording ? The rest of other groups are the committee and try to find out the faults by using some questions. ? Make a group of 5 ? I will give you 10 minutes
  • 25. Writing Create your own experiment about ¡°Atmospheric Pressure¡± by using the following materials: ? Paper ? Glass ? Water Then write on the paper and present in front of class.