ACT Preparation / Unit 22 ACT 2118 short lesson, about 20 seconds
Newton's Laws of Motion
Captions available
The idea
First law: an object stays at rest or in steady motion unless a net force acts. Second law: acceleration is proportional to net force and inversely to mass. Third law: forces come in equal and opposite pairs.
In practice
The same push accelerates an empty cart more than a loaded one.
Where people slip
Third-law pairs act on different objects, so they do not cancel.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
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