The most important equations in physics include Newton's laws of motion, Einstein's theory of relativity, Maxwell's equations of electromagnetism, and the laws of thermodynamics.
The fundamental units in physics are length (meter), mass (kilogram), time (second), electric current (ampere), temperature (kelvin), amount of substance (mole), and luminous intensity (candela).
A scalar quantity is a physical quantity that only has magnitude, while a vector quantity has both magnitude and direction. Examples of scalar quantities include mass and temperature, while examples of vector quantities include velocity and force.
The SI (International System of Units) is the most commonly used system of units in physics. It is a decimal-based system that uses seven base units and is used to measure physical quantities in a consistent and standardized way.
To convert between units in physics, you can use conversion factors or equations that relate the two units. It is important to pay attention to the units in calculations to ensure accuracy and consistency.