Answer :

In order to find the unit rate in mi / h of 14 m / s. We first have to elicit the conversion values for each unit of measurement, this will allows us identify how much will we multiply in order to get the goaled value. 
Conversion values: 
1.    1 m = 0.000621371 mi
2.    1 s = 0.000277778 h

Solution: 
1.    14 m x 0.000621371 mi /1 m = 0.0086992 mi
2.    1 s x 0.000277778 h / 1 s = 0.000277778 h

Thus, 31.32 mi/hr