Final answer:
In the context of forces, Fnet refers to the net external force acting on an object, proportional to the acceleration and inversely proportional to the mass, expressed as Fnet = ma.
Step-by-step explanation:
In physics, the term Fnet refers to the net external force acting on an object, which is the vector sum of all external forces. According to Newton's second law of motion, Fnet is directly proportional to the acceleration (a) of the object and inversely proportional to its mass (m). The equation representing this relationship is Fnet = ma, where m is the mass of the object and a is the acceleration. This law also allows us to define the units of force—specifically the newton (N), which is the force required to accelerate a 1-kg mass at a rate of 1 meter per second squared (1 m/s²).