If you run 40 yards in 4.5 seconds how many miles per hour is that?

Well, let's see here. If you run 40 yards in 4.5 seconds, that's like running about 120 feet in a little over 4 seconds. If we convert that to miles per hour, it would be around 16.36 miles per hour. Just imagine yourself running through a beautiful forest, feeling the wind in your hair at that speed!