Which law states that objects in motion stay in motion or at rest stay at rest unless acted upon by a net external force?

Which law states that objects in motion stay in motion or at rest stay at rest unless acted upon by a net external force?

• A. Hooke's Law
• B. Archimedes' Principle
• C. Law of Conservation
• D. Newton's First Law

Answer: (D)

Inertia governs how motion changes. Newton's First Law says that if the total external force on an object is zero, its velocity stays the same: an object at rest stays at rest, and an object in motion keeps moving at a constant speed in a straight line. Only a net external force can change that motion, which is why a moving puck on nearly frictionless ice keeps gliding until friction or another force slows or redirects it. This idea explains everyday observations and is what this statement is testing. Hooke's Law describes springs and how force relates to displacement; Archimedes' Principle explains buoyancy in a fluid; the Law of Conservation (in its various forms) speaks to conserved quantities like energy or momentum, not the persistence of motion in the absence of forces.

Inertia governs how motion changes. Newton's First Law says that if the total external force on an object is zero, its velocity stays the same: an object at rest stays at rest, and an object in motion keeps moving at a constant speed in a straight line. Only a net external force can change that motion, which is why a moving puck on nearly frictionless ice keeps gliding until friction or another force slows or redirects it. This idea explains everyday observations and is what this statement is testing.

Hooke's Law describes springs and how force relates to displacement; Archimedes' Principle explains buoyancy in a fluid; the Law of Conservation (in its various forms) speaks to conserved quantities like energy or momentum, not the persistence of motion in the absence of forces.