What is the metric unit of force equivalent to 1 kg m/s²?

The metric unit of force that is equivalent to 1 kg m/s² is the Newton. This unit is named after Sir Isaac Newton in recognition of his work in classical mechanics, specifically his second law of motion, which states that force equals mass times acceleration (F = ma). In this context, when a mass of 1 kilogram is accelerated at a rate of 1 meter per second squared, the resulting force is defined as 1 Newton.

Other units listed in the choices serve different purposes: Joules measure energy or work done (where 1 Joule is equivalent to 1 Newton-meter), pounds are a unit of force used primarily in the imperial system, and Watts measure power (specifically, the rate of energy transfer). Therefore, the Newton is the only correct metric unit listed that directly relates to the definition provided in the question.