1. The problem statement, all variables and given/known data A Cadillac with a mass of 2000kg approaches a freeway underpass that is 10m across. at what speed must the car be moving, and how long would it take to go the 10m, in order for it to have a wavelength such that it might somehow diffract after passing through this single "slit"? How do these conditions compare to normal freeway speeds of 30m/s? 2. Relevant equations ??? 3. The attempt at a solution ??? well, I have no idea how to solve this question... first of all, I cannot imagine what's going on here, partly because i'm not a native english speaker... Can someone teach me the way to solve this, in detail? the answers are 3.3*10^-38 m/s and 9.6*10^30 yr.