We have to convert 50 feet per second to miles per hour.
We will use the relation 5280 ft = 1 mi.
Then, we can use unit rates to convert the units as:
NOTE: The factors (1 mi / 5280 ft) and (3600 s / 1 h) have a value of 1, as numerator and denominator are equivalent, so they don't change the absolute value of the measure, but they let us change the units to the ones that we want.
Answer:
50 ft/s = 34.09 mi/h