What is the standard atmospheric pressure when doing physics problems?

Yes, 10 5pa is the approximate value, for ease of calculation.

The standard is the former, but the latter is simpler, so the latter is generally used.

1 standard atmosphere = 760 mm Hg = 76 cm Hg = Pascal = meter water column.

4 cm at 0 degrees Celsius, 24 cm at 100 degrees Celsius, where the length of 20 cm is 100 degrees Celsius, where the length of one degree of mercury is centimeters, and the length of mercury at 20 degrees Celsius is 20 * centimeters plus 4 centimeters when 0 degrees Celsius, a total of 20 degrees Celsius is 8 centimeters in length of mercury, this question needs to understand what is the definition of Celsius, the temperature of the ice-water mixture at standard atmospheric pressure is defined as 0 degrees The temperature at which pure water boils is defined as 100 degrees The middle 100 equal parts For Celsius, you can check the definition of physics books, and it's been 5 years since I graduated from college, and I can't remember.

Multiply by 10 to the 5th power of Pa, 76 cm Hg, 10 m of water.

1.The phenomenon is a column of water rising in a glass tube. Because when the temperature of the heated air in the tube decreases, the pressure of the internal gas decreases, and the water is pressed up under the action of atmospheric pressure.

2.Eggs (been.)"Swallow"to the bottle).proof (the presence of atmospheric pressure).

3.will (collide) because the flow velocity of the inside is not (less than) the outside.

1 standard atmosphere = 760 mm Hg = 76 cm Hg = Pascal = meter water column. Standard Atmospheric Pressure Values and Their Changes The regulations of standard atmospheric pressure values have undergone several changes with the development of science and technology. The atmospheric pressure at sea level at a temperature of 0 degrees Celsius, latitude 45 1 7 and on a sunny day was originally defined as standard atmospheric pressure, which was equivalent to a height of about 76 cm Hg.

Later, it was found that the atmospheric pressure value under this condition is not stable, and it varies according to the influence of wind, temperature, and other conditions. Therefore, 76 cm Hg height was set as the standard atmospheric pressure value. However, it was later found that the pressure value of 76 cm Hg was also unstable, and the density of mercury changed under the influence of temperature; The g-value also varies with latitude.

The atmospheric pressure not only varies with altitude, but also does not remain fixed at the same location, and the atmospheric pressure of the PA is usually called the standard atmospheric pressure. It is equivalent to the pressure generated by a 760mm mercury column. The value of standard atmospheric pressure is often taken as pa (101kpa) in general calculations, and can also be taken as 10 5pa (100kpa) in rough calculations.

1 standard atmosphere = 760 mmHg (millimeters of mercury) = meters of water) = Pa (Pascal). Since the density of gases is small, it is generally believed that the pressure of the gas is independent of the altitude, which means that the atmospheric pressure is considered to be constant within a certain altitude range of the earth's surface. Of course, in fact, the atmospheric pressure decreases with the increase of altitude, but the amount of reduction is very small and negligible.

1.Standard atmospheric pressure, the pressure at sea level under standard atmospheric conditions, the value of which is, is a unit of pressure, denoted as atm. At one time, the standard temperature and pressure (STP) was defined in chemistry as 0°C (and, but since 1982, IUPAC has redefined the "standard pressure" as 100 kPa).

Standard atmospheric pressure = 760 mm Hg = 76 cm Hg = water column. 1 standard atmosphere: 101325 n. Mercury = Mercury gh = =

1 standard atmosphere = 760 mm Hg = 76 cm Hg = Pascal = meter water column.

The SI unit of air pressure is Pascal (or Pascal for short, the symbol is Pa). In general meteorology, people use hectopascals (HPA) as a unit. The instrument that measures air pressure is called a barometer.

In addition to SI units, there are two commonly used units of barometric pressure: bar (1 bar = 1000 hpa) and millimeter mercury column. The average air pressure at sea level is about 10 pascals (760 mm of mercury), and this value is also known as standard atmospheric pressure.

1 standard air pressure is from 0 meters above sea level, that is, the plane as the benchmark, the calculation is the absolute vacuum state, at the sea level I wish the landlord good luck, thank you for adopting.

1 standard atmosphere = 760 mm Hg = 76 cm Hg = Pascal = meter water column.

Atmospheric pressure is not fixed. In order to compare the magnitude of atmospheric pressure, at the 10th International Conference on Weights and Measures in 1954, scientists set a "standard" for atmospheric pressure: at sea level at latitude 45°, when the temperature is 0, the pressure generated by the 760 mm high mercury column is called standard atmospheric pressure.

Since it is a "standard", it is necessary to pay attention to the accuracy of the values of each physical quantity when calculating according to the liquid pressure formula. From the relevant information, it was found that the density of mercury at 0 was kilogram m3, and the g value at sea level at latitude 45° was Ox kilograms.

The pressure generated by the 760 mm high mercury column is obtained.

P mercury = mercury gh

Kilogram m3 N Kilogram m.

Handkerchief. This is the value of 1 standard atmosphere.

The atmosphere decreases by 40 1 mm Hg = 40 mm Hg.

The atmospheric pressure at this point is 760 mmHg - 40 mmHg = 720 mmHg.