Final answer:
Pressure is conventionally measured in psi, and it is the force exerted per unit area. The SI unit of pressure is the pascal, and other units include kilopascals and atmospheres.
Step-by-step explanation:
Pressure is often measured in pounds of force per square inch of an object, also known as psi (pounds per square inch). Pressure itself is defined as the force exerted per unit area. The SI unit for pressure is the pascal (Pa), which can also be expressed in kilopascals (kPa) or as atmospheres (atm) in different contexts, such as weather reporting or blood pressure measurements.
When it comes to gases, pressure is a critical physical property and is measured using instruments like barometers and manometers. For example, barometric pressure, or the pressure exerted by Earth's atmosphere, is about 101 kPa or 14.7 lb/in.² at sea level. The measurement units range from pascals in the metric system to pounds per square inch in the U.S. customary system, and understanding the relationship among these units is essential in fields like engineering and meteorology.