[tex]1m=3.28ft\\\\1mi=5280ft\to1ft=\frac{1}{5280}mi\\\\1m=3.28\times\frac{1}{5280}\ mi=\frac{3.28}{5280}\ mi=\frac{328}{528000}\ mi=\frac{41}{66000}\ mi\\\\1h=3600s\to1s=\frac{1}{3600}h\\-------------------------\\14\ m/s=(14\times\frac{41}{66000}:\frac{1}{3600})\ mph=(\frac{574}{66000}\times3600)\ mph\\\\=(\frac{574}{55}\times3)\ mph=\frac{1722}{55}\ mph\approx31\ mph[/tex]
