Instantaneous speed is the speed of an object at a particular moment in time.
Instantaneous speed is a scalar quantity and its SI units is meters per second.
Formula to calculate instantaneous speed.

Δ means change in
x(t) = position as a function of time.
t = time (s)
Example:
Calculate the instantaneous speed if the x(t) function is 5t² and it’s in meters time t is 7 seconds.

Therefore, the instantaneous speed at 7 seconds is 70m/s.