What are the units of force as defined in the metric system?

The units of force in the metric system are defined as Newtons. This unit is named after Sir Isaac Newton, who is renowned for his work in physics, particularly in formulating the laws of motion. A Newton is the amount of force required to accelerate one kilogram of mass by one meter per second squared.

This definition is grounded in the fundamental relationship between mass, acceleration, and force as expressed in Newton's second law of motion (F = ma), where F is force, m is mass, and a is acceleration. Therefore, recognizing that force is a product of mass and acceleration helps to appreciate why Newtons are the appropriate metric unit of force.

In contrast, the other units mentioned are not used to measure force in the metric system. Watts are units of power, pounds are units of force in the imperial system, and kilograms measure mass, not force. This distinct classification supports why Newtons stand out as the correct choice for measuring force in metric terms.