We will determine the final speed as follows:
[tex]v_{\text{f}}=\frac{850m}{4.22s}\Rightarrow v_f=201.4218009m/s[/tex][tex]\Rightarrow v_f\approx201m/s[/tex]
So, superman's final velocity is approximately 201 m/s.
[In this case superman's initial velocity is a datapoint that is not necessary]
