To find the magnitude of a vector, take the components, square them, then add them, then take the square root. This is very similar to the Pythagorean Theorem.
For your particular problem, I’ve included a picture showing how that specific calculation is done. :)
Answer:
I need to see the statements to answer your question
(14 meter/sec) x (1 mile/1609.344 meter) x (3,600 sec/hour) =
(14 x 3600) / (1609.344) = <em>31.32 mile/hour </em>(rounded)