Natwerk Designs

My son has this one last Physics question and he's stuck. Can someone help with the solution?

The stoplights on a street are designed to keep traffic moving at 31 mi/hr. The average length of a street block between traffic lights is about 80 meters. What must be the time delay between green lights on successive blocks to keep the traffic moving continuously? Answer in units of seconds. eriknn, thanks! how did you get the 13.85 m/s?

Public Comments

1. 31 miles/hour = 13,85 meters/second 80 meters / 13,85 meters/seconds = 5,77 seconds.