Yesterday I took a tour of the new Dallas Cowboy stadium and it is an engineering marvel. Above the field is a mammoth 4 sided scoreboard/screen, the bottom of which is 90 feet off the playing field. (Its length extends from 20 yard line to 20 yard line) There is debate as to whether that is too low and may be hit by punts. I’ve read that the average hang time for an NFL punt is 4.6 seconds. To calculate the height I used the following reasoning, does this seem sound? Discounting aerodynamics, a punted football will follow a parabolic arc, with exactly half it’s time traveling upwards, and the other half downward. That’s 2.3 seconds going up and 2.3 seconds going down. Using the formula y= (0.5)(32.2 ft/s sq)(time squared). I calculate the average height based on average hang time is 85.2 feet. A hang time of 4.73 seconds and above translates to 90 feet and higher height. Does this seem correct? I am ignoring velocity/trajectory in the x direction, and only working in the vertical (y) based on time of flight.