Answer
The instantaneous velocity of the object at any time t during its motion is given by $f'\left( t \right)=\underset{h\to 0}{\mathop{\lim }}\,\frac{f\left( t+h \right)-f\left( t \right)}{h}$.
Work Step by Step
If a function $f\left( t \right)$ expresses an object’s position in terms of time, then: find the derivative of that function with respect to time and that will give the instantaneous velocity of the object.
Thus, the instantaneous velocity of the object at any time t during its motion is given by $f'\left( t \right)=\underset{h\to 0}{\mathop{\lim }}\,\frac{f\left( t+h \right)-f\left( t \right)}{h}$.