Which unit measures pressure in the SI system?

Pressure in the SI system is measured in pascals (Pa), where 1 pascal is defined as one newton per square meter. The kilopascal (kPa) is a commonly used unit, representing 1,000 pascals, and serves as a practical scale for typical pressures encountered in various applications. This use of kPa is especially prevalent in fields like engineering, meteorology, and physics, where pressures need to be expressed in manageable numbers rather than in the smaller unit of pascals.

Other options deal with different physical quantities: kilonewtons (kN) measure force, kilonewtonmeters (kNm) measure torque or moment, and kilonewtons per meter (kN/m) represent linear load or pressure distributed over a length. These units do not directly describe pressure, which is specifically defined as force per unit area. Consequently, kPa stands out as the appropriate choice for measuring pressure in the SI system.