40 km/h to in/s
60*60=3600 seconds in an hour
one km is about 0.621 miles
40 km is about 0.621*40=24.84 miles
5280 feet in a mile
12 inches on each foot
5280*12=63360 inches in a mile
63360*24.84=1573862.4 inches in 40km
40 km/h = 40*1573862.4/3600=17487.36 in/s