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, …

Oops. Something went wrong. Please try again. Uh oh, it looks like we ran into an error. You need to refresh. If this problem persists, tell us.

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

Let me drop my physics textbook slightly above my desk. Because of gravity the book falls down, right, yet then it’s stopped by the desk. Now the desk exerts a normal force upon the book. Without it – …

Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a …

Bem-vindo aos conteúdos de Física! A Física é o estudo da matéria, do movimento, da energia e da força. Aqui, você pode pesquisar vídeos, artigos e exercícios por tópico. Mantemos os conteúdos …

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

说实话，很难确切地定义什么是物理。首先，物理学随着我们的进步和新发现而不断变化。新理论不仅带来了新的答案。它们还产生了新的问题，从以前的物理学理论来看，这些问题甚至可能没有意义。这 …

Ojej, coś poszło nie tak. Spróbuj ponownie. Ups, wystąpił błąd. Aby kontynuować, odśwież stronę. Jeśli ten problem będzie się powtarzać, powiedz nam.

Unit 1: Forces and Newton's laws of motion About this unit For our most up-to-date, mastery-enabled courses, check out High School Physics, AP Physics 1, and AP Physics 2!