Speed and Displacement (Leaving Cert Physics): Flashcards

Rate at which distance changes with respect to time

Scalar (magnitude only, no direction)

$\text{m s}^{-1}$ or $\text{m/s}$ (metres per second)

$\text{Speed} = \frac{\text{distance}}{\text{time}}$

Overall speed for entire journey when speed varies

$\text{Average speed} = \frac{\text{total distance}}{\text{total time}}$

Exact speed at one specific moment in time

Measure average speed over very short time interval

Speed stays same, neither speeds up nor slows down

When speed is constant

Distance in specific direction from start to end

Vector (has magnitude and direction)

Distance: total path; displacement: straight-line with direction