Velocity vs. Acceleration

Velocity and acceleration describe the motion of an object and are related. Both are measurable quantities with magnitude and direction. However, there are similarities and differences between the two.

Velocity is a measure of the rate of change of displacement. When an object moves from one position to another, it is said to be displaced. The value of displacement over time gives the velocity. Its direction is along the displacement.

On the other hand, acceleration measures the rate of change in velocity. The object may change its speed or direction while keeping the speed constant. In both cases, it experiences acceleration. While acceleration refers to an increase in speed over time, its opposite, when the speed decreases with time, is called deceleration.

Difference Between Velocity and Acceleration

The table below shows the significant differences between the two.

Property	Velocity	Acceleration
Definition	Rate of change of displacement	Rate of change of velocity
Nature	Vector. It has both magnitude and direction.	Vector. It has both magnitude and direction.
Symbol	v	a
Formula	Velocity = Change in displacement/Time interval v = Δx/Δt	Acceleration = Change in velocity/Time interval a = Δv/Δt
SI unit	Meters per second or m/s	Meters per second squared or m/s2
Imperial unit	Feet per second or ft./s	Feet per second squared or ft./s2
Value	It can be positive and negative. Zero velocity implies that the object is stationary.	It can be positive and negative. Zero acceleration implies that the object is moving with a constant velocity.