Why You Can't Hear Doppler Effect in Car/Train Scenario

[crosbykins]

Homework Statement

-You are traveling in a car near a speeding train. The train whistle blows but you fail to hear the doppler effect. What conditions might prevent you from hearing it?

Homework Equations

The Attempt at a Solution

-Ok, all I can come up with is that maybe the car and train are traveling at the same velocity, so there would be no doppler effect or maybe the train is traveling at a speed greater than mach 1. Are these correct reasons?? Please help, thanks in advance.

 

[Antiphon]

Your first guess is correct. Your second guess is wrong but freaking awsome- a supersonic train. I'd like to see the wheel and rail design of such a thing. Would a steel wheel rolling along at 1000 miles per hour even be able to hold together?