Answer
These procedures are equivalent if we look at the graph of the function $s(t)$ that says what is the position at the given time $t$.
Work Step by Step
These procedures are equivalent:
1) The average velocity on the time interval $[t,t+h]$ is equal to the slope of the secant line through the points $(t,s(t))$ and $(t+h,s(t+h))$ on the graph of the position versus time $s(t)$
2) As we make $h$ smaller and smaller the average velocity will become closer and closer to the instantaneous velocity, while the slope of the secant line through the mentioned points will become closer and closer to the slope of the tangent at $(t,s(t))$
3) The instantaneous velocity is actually equal to the slope of the tangent at $(t,s(t))$, where $s(t)$ is the position at time $t$.
