What is measured by the force of gravity acting on an object?

The correct answer is weight, which is defined as the force exerted by gravity on an object. Weight is determined by the mass of the object and the acceleration due to gravity acting on it. The formula for weight is W = mg, where W represents weight, m stands for mass, and g is the acceleration due to gravity.

In this context, while mass measures the amount of matter in an object and is constant regardless of location, weight varies based on the gravitational pull acting on that mass. For example, an object weighs less on the Moon than on Earth due to the Moon's weaker gravitational force, even though its mass remains unchanged. Volume refers to the space occupied by an object, and density is the mass per unit volume. These concepts, although related to physical properties, do not directly involve the gravitational force acting on an object. Thus, weight is the specific measurement that relates to the force of gravity.