Pascal: The SI Unit of Pressure

The question asks to identify the physical quantity for which Pascal (Pa) is the SI derived unit. Let's analyze the options provided.

The Pascal (Pa) is a fundamental unit in the International System of Units (SI). It is named after the French physicist Blaise Pascal.

• Option 1: Pressure
  Pressure is defined as force per unit area. The SI unit of pressure is indeed the Pascal (Pa). One Pascal is defined as one Newton per square meter ($$1\text{ Pa} = 1\text{ N/m}^2$$). This aligns perfectly with the definition of pressure.
• Option 2: Force
  Force is a push or pull that can cause an object to accelerate. The SI unit of force is the Newton (N), named after Isaac Newton. Therefore, Pascal is not the SI unit of force.
• Option 3: Frequency
  Frequency is the number of occurrences of a repeating event per unit of time. The SI unit of frequency is the Hertz (Hz), named after Heinrich Hertz. Therefore, Pascal is not the SI unit of frequency.
• Option 4: Thrust
  Thrust is a reaction force described quantitatively by Newton's third law. It is the force that propels an aircraft, rocket, or other vehicle. As thrust is a force, its SI unit is also the Newton (N). Therefore, Pascal is not the SI unit of thrust.

Based on the standard definitions of SI units, the Pascal (Pa) is the SI derived unit specifically for pressure.

Here is a summary of the SI units for the quantities mentioned:

Therefore, the Pascal is the SI derived unit of Pressure.