# Sound Waves

A series of free Online High School Physics Video Lessons.

In these lessons, we will learn

• Sound Waves

• Standing Sound Waves

• Wave Intensity

• Decibel Scale

### Sound Waves

Sound waves are waves transmitted through the air or even through liquids or solids which change the pressure of that substance enough that our ears can perceive them. The pitches of sounds we hear depend on varying frequencies of these waves.

Understanding sound waves.
A brief introduction to characteristics and attributes of sound waves
Understand the nature of sound waves
Sound Properties (Amplitude, Period, Frequency, Wavelength)

### Standing Sound Waves

The standing sound waves are known as harmonics that involved sound. Standing sound waves associate with the boundary conditions at the boundaries of the medium. When the traveling wave is reflected back into the medium, energy stands in the way. The two boundary positions are open boundary condition in which the air is open and closed boundary in which the air is blocked from the surrounding. The position of standing waves varies accordingly to the boundary conditions, pressure, and displacement.

Understanding standing sound waves.
Standing Waves and Harmonics

This video shows the three-dimensional nature of sound. As visitors scroll through different frequencies using a dial, a tone generator creates standing sound waves in a clear acrylic tube filled with Styrofoam pellets. The tube is approximately 36" long and 5" in diameter, allowing the standing sound waves to form in a clearly visible way. By experimenting with a range of tones, we can discover that different sounds have unique wavelengths and shapes.

### Wave Intensity

Wave intensity is the average power that travels through a given area as the wave travels through space. The intensity of sound waves is measured using the decibel scale.

Understanding the concept of the intensity or energy of waves.
Wave Amplitude and Intensity
If you double the amplitude of a wave you give it four times as much energy, this leads on to the relationship between amplitude and intensity of a wave.

Wave Intensity

### Decibel Scale

The decibel scale is used to measure the intensity of sound waves. A wave with an intensity of 0 decibels is impossible to hear. Normal speech, on the other hand, has an intensity of 60 decibels.

Understanding the decibel scale.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.