Bump-bump

[doormouse11]

When driving over a speedbump, the bump sound made by the back tires hitting the bump always seems higher pitched than the sound made by the front tires hitting the bump (my boyfriend and I drove over speedbumps as much as possible on the way to lunch yesterday to confirm that we actually heard it). Does anyone know why?


We thought it might be related to the dopplar effect but wouldn't that make the back tires have the lower pitched sound?

[Da5id]

Don't drive over them backwards.

[Jack_Ian]

Hit the front of your car with a large hammer and then repeat the process with the rear of your car.
You will probably find that the bang sounds different.
In fact, it would be quite difficult to find 2 places that sound exactly the same, feel free to try it out if you wish.
For a safer experiment, stand near a speed bump and get your boyfriend to drive over it.
You should still hear the different sounds even though you are not in the car or moving relative to the speed-bump.

[extro...]

Somewhat unrelated, but amusing: I found that if I have my windsheild wipers on at the right speed while the car is stationary (like at a red light), in a short time the car starts rocking from side to side. This doesn't work when other people are in the car - apparently the change in weight changes the natural rocking frequency of the car, which the wipers seem to be synchronized with.

[One Skunk Todd]

Maybe it makes a different sound because the front end of the car is so much heavier?

[Doc Borodog]

doormouse11,

My first guess is that the rear suspension is probably stiffer.

[doormouse11]