Question

a. Identify three units used to express pressure. b. Convert one atmosphere to millimeters of mercury. c. What is a pascal? d. What is the SI equivalent of one standard atmosphere of pressure?

Short answer

a. atm, mmHg, Pa. b. 1 atm = 760 mmHg. c. 1 Pa = 1 N/m². d. 1 atm = 101,325 Pa.

Step-by-step solution

Identify Units of Pressure

Three common units used to express pressure are atmospheres (atm), millimeters of mercury (mmHg), and pascals (Pa).

Convert Atmosphere to Millimeters of Mercury

To convert one atmosphere to millimeters of mercury, use the conversion factor: 1 atm = 760 mmHg. Thus, 1 atm is equal to 760 mmHg.

Define Pascal

The pascal (Pa) is the SI unit for pressure and is defined as one newton per square meter. It is a relatively small unit of pressure compared to atmospheres or millimeters of mercury.

SI Equivalent of One Atmosphere

One standard atmosphere (1 atm) is equivalent to 101,325 pascals (Pa) in the International System of Units (SI).

Key concepts

pressure measurement

Pressure is a measure of force applied over a unit area. It's fundamental in understanding various scientific and engineering phenomena. There are different units to express pressure based on the system being used. Here are three common ones:

• Atmospheres (atm)
• Millimeters of mercury (mmHg)
• Pascals (Pa)

These units provide flexibility for different applications, whether it’s in meteorology, medicine, or physical sciences.
Let's break these units down to see their individual characteristics.

atmosphere conversion

Atmospheric pressure at sea level is often considered to be 1 atmosphere (atm). This unit is useful in many practical scenarios.
To convert atmospheres to millimeters of mercury, we use the conversion factor:
1 atm = 760 mmHg
This means when the atmospheric pressure is at one atmosphere, it exerts the same pressure as a 760 mm high column of mercury.
This conversion is handy in barometric readings where pressure is often measured in mmHg.

pascal definition

The pascal (Pa) is the Standard International (SI) unit for pressure. It is named after Blaise Pascal, a French mathematician, physicist, and inventor.
A single pascal is equal to one newton per square meter: \( 1 \text{ Pa} = 1 \frac{N}{m^2} \)
Since it is a small unit, it's often more convenient to express pressure in kilopascals (kPa), where 1 kPa = 1000 Pa.
This unit is essential in areas like material science, where precise calculations of pressure are necessary.

SI units

The International System of Units (SI) provides a consistent framework for measuring various physical quantities. Pressure is one of these quantities and the SI unit for pressure is the pascal (Pa).
We've seen that standard atmospheric pressure is equal to:
1 atm = 101,325 Pa
This equivalence means that one atmosphere of pressure is the same as 101,325 pascals.
Such conversions are crucial in fields that rely on precise and standardized measurements, ensuring clear communication and accurate results.