If a car is traveling at 40 miles per hour on a country high

If a car is traveling at 40 miles per hour on a country highway, what is its spped in feet per second?

Solution

1 hour
.
Now, we multiply by equivalent units until we get our desired units.
.
40 miles 1 hour 1 min 40 miles
-------- x -------- x ------ = ---------
1 hour 60 mins 60 sec 3600 sec
.
Now, we convert the miles:
.
40 miles 5280 feet (40*5280) feet
--------- x ----------- = --------------
3600 sec 1 mile 3600 sec
.
(40*5280) feet
-------------- = 58.67 feet/sec
3600 sec