Final answer:
Doubling the mass of a moving object doubles its inertia and thus its resistance to changes in motion. It also doubles the object's weight, which is the gravitational force exerted on it.
Step-by-step explanation:
If the mass of a moving object is doubled, then according to Newton's Second Law of Motion (Force = mass x acceleration), the inertia of the object would double as well. Inertia is a property of matter that describes its resistance to any change in its state of motion. Hence, if the mass of an object is doubled, its inertia, or the resistance to changes in its motion, would also be doubled. However, if we specifically discuss the weight of an object, which is the force exerted by gravity on the object, then doubling the mass of an object would indeed double its weight (since weight = mass x acceleration due to gravity). It's important to note that the weight of an object is different from its mass, as weight is a force while mass is a measure of the amount of matter.