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
