This is not a homework problem, I just want to know if this is possible. The cop is traveling in the opposite direction of me. Let's say I'm going 60mph and am speeding. He turns around, catches up to me, and clocks me going 15mph over the speed limit. Is this even possible? I found this link: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/radar.html, but the cop is stationary. Does radars even work this way? Curious to know, thanks!