How can you demonstrate that a sound is a wave?

Answer 1

Simple, have someone drive towards you blowing the horn. You will notice that the PITCH of the horn changes as it grows nearer and when it passes you it pitch goes lower. A DC sound wave would NOT do this. The reason is as the car approaches you are compressing the sound wave making it higher pitch than normal(car standing still) and stretching the wave after it passes making the pitch lower that normal. I can't draw a diagram but if I could it would explain it alot easier. Trust me it's a wave.Another experiment would be to place a speaker in water( yes it can be done)and play some music. The waves in the water will mimic the sound waves and make them visible. Don't try this at home there are special considertaions to take into account.You can if you don't care about the speaker or amp and find someone very knowledgable about both to run it.