Sound

Sound Waves

Now, you will be introduced to the wave properties of sound. View the presentation on sound to learn about some phenomena commonly associated with sound waves. Click the player to begin.

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An extreme example of resonance occurred in November of 1940 near Tacoma, Washington. Just as a reed in a clarinet will vibrate at its natural frequency when air is blown past it by a musician, the Tacoma Narrows Bridge was known to oscillate at its natural frequency when strong winds blew past it. This suspension bridge was known as “Galloping Gertie." It would wobble back and forth rhythmically and often violently. On November, 17, 1940, these oscillations caused the bridge to collapse into the river. View the video clip Tacoma Narrows Bridge from Discovery Education™ streaming to see the oscillation and eventual collapse of the bridge.

Did you know that you can see a sonic boom in action?  View the video clip Capturing a Sonic Boom on Camera from Discovery Education™ streaming to see what a sonic boom sounds like and looks like. This video shows the production of a sonic boom in slow motion. As the pressure of the sonic boom passes through the air, it temporarily creates a cloud in the shape of the shock wave. You can even see the distortion of the sound barrier breaking.

Below are two images of boats moving at speeds quicker than the speed of water waves. The wake of the boat forms the classic cone shape expected from the Doppler effect.

Now that you are familiar with sound, you should try to work out the following problems before looking at the provided solutions. Make sure to click submit after answering each question. Click the player button to get started.