Physics uses simple yet elegant math to describe complex phenomena, from galaxies to biological systems. It's about understanding and predicting the universe's complexity based on simple ideas.

The physics archive contains legacy physics content, and is not being updated with new content. For our most up-to-date, mastery-enabled courses, check out Middle School Physics, High School Physics, …

Let's think about what physics is and what topics are covered in an introductory physics course.

In this high school physics course, we'll answer all these questions and many more. Physics is the science of building models to explain how the universe works.

Welcome to AP®︎/College Physics 1! In AP Physics 1, you'll learn algebra-based classical mechanics. To make sure you’re prepared with the fundamentals, we recommend completing high school …

From the tiniest grains of sand to the biggest stars in our cosmos. But, they defy Newton's laws. To understand them, we need a new set of principles called quantum mechanics which we introduce in …

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Explore high school physics topics including forces, motion, energy, electromagnetism, and light, from stars to subatomic particles.

Learn physics using videos, articles, and NGSS-aligned practice exercises. Explore the fundamentals of motion and forces, non-contact interactions, energy, and waves.

Well, it's not normal, abnormal kind of normal. Normal in physics or math means perpendicular. So it's representing perpendicular. And you can see what it means is that this force is perpendicular to the …