Vectors vs. Scalars: The Foundation You Cannot Skip
Why getting comfortable with direction early makes the rest of mechanics far easier.
A scalar has magnitude only — mass, time, speed. A vector has magnitude and direction — displacement, velocity, force. Mixing them up is the single most common source of early mistakes in mechanics.
The trick is to always draw the direction. Once you represent vectors as arrows and resolve them into components, problems that looked intimidating become routine bookkeeping.