Question

states that an object at rest will remain at rest, and an object in motion will remain in motion unless acted upon by an unbalanced force. inertia is the tendency of an object to resist a change in motion. an object at rest will remain at rest until when? the density of the object is changed the volume of the object is changed an unbalanced force acts upon the object

Explanation:

According to Newton's First Law of Motion, an object at rest remains at rest until an unbalanced force acts on it. The other options (changing density or volume) do not relate to the conditions for an object to start moving as per this law.

Answer:

An unbalanced force acts upon the object