Massachusetts Tests for Educator Licensure (MTEL) Practice Test

What is the relationship between mass and an object's resistance to changes in motion?

1. Mass is unrelated to resistance

2. More mass means less resistance

3. Resistance increases with mass

4. Mass determines only the weight of an object

The correct answer is: Resistance increases with mass

The relationship between mass and an object's resistance to changes in motion is indeed encapsulated in the concept of inertia, which is the tendency of an object to resist changes to its state of motion. The greater the mass of an object, the greater its inertia, meaning it will require more force to change its motion—whether that's starting it moving, stopping it, or changing its direction. As mass increases, the amount of resistance to changes in motion correspondingly increases. This principle is articulated in Newton's first law of motion, which states that an object in motion will remain in motion and an object at rest will remain at rest unless acted upon by a net external force. Therefore, when mass is greater, the force required to alter that object's motion increases, which directly correlates with increased resistance to motion changes. While the choices present various interpretations of mass and resistance, the correct choice highlights this foundational physical principle, linking mass with the degree of resistance an object exhibits when subjected to forces.