The introduction to physics you get in this site will explain laws and principles that are accepted as of today. Physics is a progressive science as scientists change their mind all the time, so don’t be shock when a change is made. Key concepts of force, including various forms of force and how friction works. Key concepts of waves, including: their properties with a focus on sound waves, interference and diffraction of waves, and stationary waves and resonance.
Lecture on Introductory Physics
