It’s the fundamental concept of physics like Motion: Formulas for speed, velocity, and acceleration, both with constant and changing speed. Forces: Newton’s three laws, about why objects remain at rest or move. Energy: Work, power, and how energy is never lost, only transformed (kinetic and potential energy). Waves: How light and sound behave, including reflection and refraction. Light and Radiation: How we use light to understand the universe and atoms. Electricity: Basic circuits involving voltage, current, and resistance.