Answer
Conjecture: the instantaneous velocity at $t=1$ is $48$.
Work Step by Step
Over $[1,1.01]$,
$v_{\mathrm{a}\mathrm{v}}= \displaystyle \frac{s(1.01)-s(1)}{0.01}=47.84$,
Over $[1,1.001]$,
$v_{\mathrm{a}\mathrm{v}}= \displaystyle \frac{s(1.001)-s(1)}{0.001}=47.984$
Over $[1,1.0001]$,
$v_{\mathrm{a}\mathrm{v}}= \displaystyle \frac{s(1.0001)-s(1)}{0.0001}=47.9984$.
The average velocity appears to approach $48$ as the time interval gets shorter.
Conjecture: the instantaneous velocity at $t=1$ is $48$.
