What is the unit of force in the SI system?

The unit of force in the SI system is the Newton. This unit is defined as the amount of force required to accelerate a one-kilogram mass by one meter per second squared. It reflects the relationship between mass, acceleration, and force as described by Newton's second law of motion.

In contrast, the Joule is the unit of energy or work, which is not directly related to force. The Pound is a unit of force commonly used in the imperial system, not the SI system. The Pascal is the unit of pressure, defined as one Newton per square meter, and while it involves force, it is not the direct unit of force itself. Thus, the Newton is the most appropriate choice as it specifically and directly represents the concept of force within the SI framework.