Which statement about inertia is correct?

Which statement about inertia is correct?

• A. The force that causes an object to move
• B. The speed at which an object moves
• C. The tendency of an object to resist a change in motion or at rest
• D. The energy an object possesses due to motion

Answer: (C)

Inertia is the tendency of an object to resist a change in its motion or its state of rest. This resistance grows with mass—the more massive something is, the harder it is to start moving, speed up, slow down, or come to a stop. That’s why a heavier skier or a loaded setup requires more effort to accelerate or to halt, and why an object in motion keeps moving in the same direction unless a net external force acts on it. This description matches what inertia does: it resists changes in velocity, whether you’re starting from rest or coming out of a turn. The other descriptions point to different ideas. The force that initiates movement is a force, not inertia. Speed refers to how fast something is moving, not its resistance to changing that motion. The energy due to motion is kinetic energy, which is a measure of motion, not the resistance to changing motion.

Inertia is the tendency of an object to resist a change in its motion or its state of rest. This resistance grows with mass—the more massive something is, the harder it is to start moving, speed up, slow down, or come to a stop. That’s why a heavier skier or a loaded setup requires more effort to accelerate or to halt, and why an object in motion keeps moving in the same direction unless a net external force acts on it. This description matches what inertia does: it resists changes in velocity, whether you’re starting from rest or coming out of a turn.

The other descriptions point to different ideas. The force that initiates movement is a force, not inertia. Speed refers to how fast something is moving, not its resistance to changing that motion. The energy due to motion is kinetic energy, which is a measure of motion, not the resistance to changing motion.