Step-by-step explanation:
There are 5280 feet in a mile and 3600 seconds in an hour.
So a truck driving 45 miles an hour would be driving:
[tex]\frac{45 miles}{1 hour}[/tex] x [tex]\frac{1 hour}{3600 seconds}[/tex] x [tex]\frac{5280 feet}{1 mile}[/tex] = [tex]\frac{237600}{3600}[/tex] = 66 feet per seconds
