PhysicsGrade 11· U.S. National — Common Core & NGSS
Aligned to:NGSS (Physical Science)
Newton's Three Laws of Motion
Inertia, F = ma, and action-reaction, explained with everyday examples.
Illustrations are auto-generated and may be placeholders. They can be refreshed to match the narration.
Full teaching narration is included free with a Private Starter account.Create free account
First law: inertia
An object at rest stays at rest, and an object in motion keeps moving at constant velocity, unless an unbalanced force acts on it. This is why passengers lurch forward when a car brakes suddenly.
Second law: F = ma
Acceleration is proportional to the net force and inversely proportional to mass. A 10 N force on a 2 kg cart gives 5 m/s². The same force on a heavier cart produces less acceleration.
Third law: action and reaction
For every action there is an equal and opposite reaction. The forces act on different objects, which is why they do not cancel: a rocket pushes gas down and the gas pushes the rocket up.