Which answer correctly states Newton's First Law?

Question

answers:

An object in motion stays in motion unless an unbalanced force acts upon it.
Force is equal to the mass of an object times its acceleration (F=ma).
For every force acting on an object, that object exerts an equal force in the opposite direction on the first object.

Answer 1

The correct statement of Newton's First Law is:

An object in motion stays in motion unless an unbalanced force acts upon it.

This law is often summarized as the principle of inertia, which states that an object will maintain its state of rest or uniform motion in a straight line unless acted upon by an external force.