$${\mathtt{Fres}} = {\sqrt{{{\mathtt{F1}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{{\mathtt{F2}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{F1}}{\mathtt{\,\times\,}}{\mathtt{F2}}{\mathtt{\,\times\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{\alpha}}\right)}}}$$
$${\frac{{\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{m}}}{{\mathtt{s}}}} = {\frac{{\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{3\,600}}{\mathtt{\,\times\,}}{\mathtt{km}}}{\left({\mathtt{1\,000}}{\mathtt{\,\times\,}}{\mathtt{h}}\right)}} = {\frac{{\mathtt{18}}{\mathtt{\,\times\,}}{\mathtt{km}}}{{\mathtt{h}}}}$$