Pressure measures how force is distributed over a given area. Whether it’s the pressure of the atmosphere on your skin or the pressure inside a tire, this unit helps us understand the impact of force in a more localized way. Measured in pascals or pounds per square inch, pressure affects everything from weather patterns to engineering designs.
- Pascal (Pa): The SI unit of pressure, defined as one newton of force applied over a square meter of area. It is often used in scientific contexts, especially in physics and engineering. For example, atmospheric pressure at sea level is approximately 101,325 pascals.
- Bar (bar): A unit often used to measure atmospheric pressure, with 1 bar being close to the average atmospheric pressure on Earth at sea level. For instance, a car tire is usually inflated to around 2 to 2.5 bars.
- Pound per Square Inch (psi): Common in the United States for applications such as tire pressure, hydraulic systems, and more. One psi is the pressure exerted by one pound-force over a square inch area. For example, car tires are often inflated to around 30-35 psi.
- Atmosphere (atm): A unit based on average atmospheric pressure at sea level. It is equivalent to approximately 101,325 pascals, and used in applications like scuba diving to measure underwater pressure.
- Torr (Torr): Named after Evangelista Torricelli, this unit is used in vacuum measurements and is equivalent to 1/760 of an atmosphere, or approximately 133.322 pascals. For example, high vacuum systems may operate at pressures as low as 10^-6 Torr.
