Are there any physics lessons available for free online?

Khan Academy has an extensive video library of physics lessons available online for free. The lessons range from basic one-dimensional motion to more advanced topics, such as thermodynamics and geometric optics.

Khan Academy's videos are hosted on YouTube, but are curated on the Khan Academy website in a structured, logical fashion that provides users with a coherent learning experience. Whether one is a beginner or an advanced student, Khan Academy has videos to fit a variety of physics needs.

Studying physics requires a prior understanding of algebra and trigonometry. Luckily, Khan Academy also has a series of videos on these topics and other prerequisites.