Speed, Displacement, and Velocity (Leaving Cert Physics): Flashcards

Rate of change of displacement with respect to time

Vector (has magnitude and direction)

Scalar (magnitude only)

$v$ (or $u$ for initial velocity)

Metres per second (m s$^{-1}$ or m/s)

$\frac{\text{displacement}}{\text{time}}$

No speed up, slow down, or direction change

Velocity at a specific moment in time

When object changes speed, direction, or both

50 Hz (dots every 1/50th second)

Constant velocity

1/50 second or 0.02 s

$\frac{\text{length of card}}{\text{time to interrupt beam}}$

Direction continuously changes

Provides almost friction-free environment for studying motion