Displacement, Speed, and Velocity
Motion starts with displacement, a vector quantity that includes both distance and direction. When moving along a single axis, direction is indicated by positive or negative signs, while magnitude represents the length traveled.
Speed focuses on distance only, without considering direction. Average speed equals total distance divided by time and is always positive. This differs from velocity, which accounts for direction and is calculated as displacement divided by time interval (Vₐᵥg = Δx/Δt).
Instantaneous velocity describes motion at a specific moment, calculated as the limit of Δx/Δt as Δt approaches zero (dx/dt). The units for both speed and velocity are distance per time, typically meters per second (m/s).
Quick Tip: Remember that when calculating total distance traveled, use speed. When determining how far something has moved from its starting point, use velocity.
