What property describes an object's resistance to a change in its motion?

What property describes an object's resistance to a change in its motion?

• A. Friction
• B. Gravity
• C. Momentum
• D. Inertia

Answer: (D)

Inertia is the property that describes an object's resistance to a change in its motion. This means a heavier object, with more mass, resists changes in speed or direction more than a lighter one. According to Newton's first law, without a net external force, an object at rest stays at rest and an object in motion keeps moving in a straight line at the same speed. Mass measures how much inertia something has. Friction is a force that opposes motion, gravity is a force pulling toward Earth, and momentum is the quantity of motion (mass times velocity) that changes when a net force acts. A good way to picture inertia is to imagine pushing a heavy cart versus a light bicycle—the heavy cart resists starting and stopping more because it has greater inertia.

Inertia is the property that describes an object's resistance to a change in its motion. This means a heavier object, with more mass, resists changes in speed or direction more than a lighter one. According to Newton's first law, without a net external force, an object at rest stays at rest and an object in motion keeps moving in a straight line at the same speed. Mass measures how much inertia something has. Friction is a force that opposes motion, gravity is a force pulling toward Earth, and momentum is the quantity of motion (mass times velocity) that changes when a net force acts. A good way to picture inertia is to imagine pushing a heavy cart versus a light bicycle—the heavy cart resists starting and stopping more because it has greater inertia.