Answer
The conversion factor is 2.24
To make a quick approximation, the easiest conversion factor might be $\frac{9}{4}$ which is $2.25$
Work Step by Step
We can convert $1~m/s$ to units of $mi/h$:
$1~m/s\times \frac{3600~s}{1~h}\times \frac{1~km}{1000~m}\times \frac{0.6214~mi}{1~km} = 2.24~mi/h$
The conversion factor is thus 2.24.
To make a quick approximation, the easiest conversion factor might be $\frac{9}{4}$ which is $2.25$.
