AEMCA Practice Exam

What does Newton's first law of motion state?

1. An object at rest will stay at rest unless acted upon by an outside force.

2. All objects will accelerate equally regardless of mass.

3. Motion can be achieved without any external influences.

4. An object in motion will eventually come to rest.

The correct answer is: An object at rest will stay at rest unless acted upon by an outside force.

Newton's first law of motion, often referred to as the law of inertia, emphasizes that an object will maintain its state of rest or motion unless acted upon by an external force. This principle highlights the concept of inertia, suggesting that objects have a natural tendency to resist changes in their state of motion. Therefore, if an object is at rest, it will continue to stay at rest unless a force, such as a push or pull, is applied to it. Similarly, if an object is in motion, it will continue to move at a constant velocity in a straight line until a force, such as friction or gravity, acts upon it to change that state. In contrast, the other statements do not accurately reflect the principles outlined in Newton's first law. The assertion that all objects will accelerate equally regardless of mass misrepresents the influence of mass on acceleration, which is actually articulated in Newton's second law. The idea that motion can occur without external influences contradicts the essence of inertia, which stresses the necessity of an external force to change an object's motion. Lastly, the notion that an object in motion will eventually come to rest fails to incorporate the condition that without any forces acting on it, particularly friction, the object will continue moving indefinitely.