Newton's 1st Law describes...

• A. Newton's 2nd Law
• B. Law of Conservation
• C. Ohm's Law
• D. Newton's 1st Law

Answer: (D)

Inertia governs how motion changes (or doesn’t). Newton's First Law says an object at rest stays at rest and an object in motion keeps moving in a straight line at constant speed unless a net external force acts on it. This captures the idea that motion resists changes: without a pushing or pulling force, nothing in the motion state will spontaneously alter course or speed.

Think of a parked car: it stays put until you push it. Think of a puck sliding on a very smooth surface: it would keep gliding at the same speed and direction if there were no friction. Real life adds friction or pushes, and those are the net external forces that change the motion.

The other statements point to different ideas: one describes how force relates to acceleration (not just maintaining motion), another is about electrical behavior (voltage, current, resistance), and the last about quantities that stay constant in isolated systems. None of those capture the behavior of an object continuing in its present motion or rest unless something acts on it in the way Newton’s First Law does.