1. The problem statement, all variables and given/known data A policeman detects a drop of 10% in the pitch of the horn of a motor car as it crosses him. If the velocity of sound is 330ms^-1, calculate the speed of the car. 2. Relevant equations f2 = f1 [v - v(listener)]/[v - v(source)] where f2 = apparent frequency f1 = true frequency 3. The attempt at a solution I'm confused about how the car crosses him. Please help.