3600
0.5667
1200
45
276.9231
12.1
Speed = Distance divided by Time 1760 yards = 1 mile. 3600 seconds = 1 hour 40/1760 divided by 4.8/3600 = 17.0454545 Answer: about 17 mph TIP: put "4.8 seconds / 40 yards in mph" into google, and it will calculate it for you.
400
3.3333
18
6.6667
360