Khan Academy
Khan Academy: What Is Physics?
Article attempts to answer the question "what is Physics?" Takes a look at concepts such as force, motion, Newton's Laws, work, energy, and much more.
Khan Academy
Khan Academy: What Is Newton's Second Law?
Learn about the fact that forces cause acceleration in this article about Newton's Second Law. Includes examples and worked examples of problems.
Khan Academy
Khan Academy: What Is Hooke's Law?
Learn about elasticity and how to determine the force exerted by a spring.