This book, on college physics, is an open textbook and a free textbook at the same time: A free pdf textbook, on introductory physics, free for download, for high-school students, college students and university students.
Many things move in nature - and on the internet: therefore this page can be slow to load. Alternatively, you can browse the files of the free physics textbook also on scribd, at https://www.scribd.com/collections/2705622.
Volume II, on relativity and cosmology, is presented here.
Volume IV, on quantum physics, is presented here.
If you want to experience why physics, the science of motion, is so fascinating, think about the story of the atoms and molecules in your body: the hydrogen atomes formed in the big bang, the carbon in some star that exploded long before the Sun formed. The water molecules were collected on Earth from comets that crashed onto our planet long before life formed. And if you want to know what is so fascinating about motion around us, watch the videos on this page.
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