Which unit is used to measure pressure in the SI system?

Which unit is used to measure pressure in the SI system?

• A. Pascals (Pa)
• B. Meters (m)
• C. Joules (J)
• D. Liters (L)

Answer: (A)

Pressure is defined as force per unit area, and its SI unit is the Pascal. One Newton per square meter equals one Pascal, so Pa = N/m^2. Since a Newton is kg·m/s^2, the Pascal can be thought of as kg/(m·s^2). This relation makes sense because pressure measures how much force is applied over a given area. In practice, the Pascal is quite small, so larger units like kilopascals (kPa) or megapascals (MPa) are commonly used. For context, one atmosphere is about 101,325 Pa, or 101.3 kPa. The other units listed—meters, joules, and liters—correspond to length, energy, and volume, not pressure.

Pressure is defined as force per unit area, and its SI unit is the Pascal. One Newton per square meter equals one Pascal, so Pa = N/m^2. Since a Newton is kg·m/s^2, the Pascal can be thought of as kg/(m·s^2). This relation makes sense because pressure measures how much force is applied over a given area. In practice, the Pascal is quite small, so larger units like kilopascals (kPa) or megapascals (MPa) are commonly used. For context, one atmosphere is about 101,325 Pa, or 101.3 kPa. The other units listed—meters, joules, and liters—correspond to length, energy, and volume, not pressure.