Answer :
we know that
[tex]1\ mile=5,280\ feet[/tex]
[tex]1\ hour=3,600\ sec[/tex]
1) convert miles per hour to feet per hour
[tex]40\ miles/hour=40*5,280=211,200\ feet/hour[/tex]
2) convert feet per hour to feet per second
[tex]211,200\ feet/hour=211,200/3,600=58.67 feet/sec[/tex]
Round to the nearest whole number-------> [tex]59 feet/sec[/tex]
therefore
the answer is
[tex]59 feet/sec[/tex]