This simulation lets you see sound waves. Adjust the frequency or volume and you can see and hear how the wave changes. Move the listener around and hear what she hears.
Students learn about sound and sound energy as they gather evidence that sound travels in waves. Teams work through five activity stations that provide different perspectives on how sound can be seen and felt. At one station, students observe oobleck (a shear-thickening fluid made of cornstarch and water) “dance” on a speaker as it interacts with sound waves (see Figure 1). At another station, the water or grain inside a petri dish placed on a speaker moves and make patterns, giving students a visual understanding of the wave properties of sound. At another station, students use objects of various materials and shapes (such as Styrofoam, paper, cardboard, foil) to amplify or distort the sound output of a homemade speaker (made from another TeachEngineering activity). At another station, students complete practice problems, drawing waves of varying amplitude and frequency. And at another station, they experiment with string (and guitar wire and stringed instruments, if available) to investigate how string tightness influences the plucked sound generated, and relate this sound to high/low frequency. A worksheet guides them through the five stations. Some or all of the stations may be included, depending on class size, resources and available instructors/aides, and this activity is ideal for an engineering family event.
Students are provided with an understanding of sound and light waves through a "sunken treasure" theme a continuous storyline throughout the lessons. In the first five lessons, students learn about sound, and in the rest of the lessons, they explore light concepts. To begin, students are introduced to the concepts of longitudinal and transverse waves. Then they learn about wavelength and amplitude in transverse waves. In the third lesson, students learn about sound through the introduction of frequency and how it applies to musical sounds. Next, they learn all about echolocation what it is and how engineers use it to "see" things in the dark or deep underwater. The last of the five sound lessons introduces acoustics; students learn how different materials reflect and absorb sound.
Students follow the steps of the engineering design process to create their own ear trumpet devices (used before modern-day hearing aids), including testing them with a set of reproducible sounds. They learn to recognize different pitches, and see how engineers must test designs and materials to achieve the best amplifying properties.
Music can loosely be defined as organized sound. The lesson objectives, understanding sound is a form of energy, understanding pitch, understanding sound traveling through a medium, and being able to separate music from sound, can provide a good knowledge base as to how sound, math, and music are related. Sound exists everywhere in the world; typically objects cause waves of pressure in the air which are perceived by people as sound. Among the sounds that exist in everyday life, a few of them produce a definite pitch. For example, blowing air over half full glass bottles, tapping a glass with a spoon, and tapping long steel rods against a hard surface all produce a definite pitch because a certain component of the object vibrates in a periodic fashion. The pitch produced by an object can be changed by the length or the volume of the portion that vibrates. For example, by gradually filling a bottle while blowing across the top, higher pitches can be generated. By organizing a few of these sounds with a clearer pitch, the sounds become closer to music. The very first musical instruments involved using various objects (e.g. bells) that have different pitches, which are played in sequence. The organization of the pitches is what transforms sounds into music. Since the first instruments, the ability to control pitch has greatly improved as illustrated by more modern instruments such as guitars, violins, pianos, and more. Music is comprised of organized sound, which is made of specific frequencies. This lesson will help define and elaborate on the connections between sound and music.
Make waves with a dripping faucet, audio speaker, or laser! Add a second source or a pair of slits to create an interference pattern.
Watch a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator. Adjust the damping and tension. The end can be fixed, loose, or open.
Watch a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator. Adjust the damping and tension. The end can be fixed, loose, or open.
Students learn about the types of waves and how they change direction, as well as basic wave properties such as wavelength, frequency, amplitude and speed. During the presentation of lecture information on wave characteristics and properties, students take notes using a handout. Then they label wave parts on a worksheet diagram and draw their own waves with specified properties (crest, trough and wavelength). They also make observations about the waves they drew to determine which has the highest and the lowest frequency. With this knowledge, students better understand waves and are a step closer to understanding how humans see color.
Students are introduced to the concept of refraction. After making sure they understand the concepts of diffraction and interference, students work collaboratively to explain optical phenomena that cannot be accounted for via these two mechanisms alone. Then, through the associated activity, students see first-hand how refraction can work with interference to produce color patterns, similar to how nanosensors work. Finally, students apply their knowledge of refraction to the original challenge question to generate a possible solution in the form of a biosensor.
Students measure the wavelength of sounds and learn basic vocabulary associated with waves. As a class, they brainstorm the difference between two tuning forks and the sounds they produce. Then they come up with a way to measure that difference. Using a pipe in a graduated cylinder filled with water, students measure the wavelength of various tuning forks by finding the height the pipe must be held at to produce the loudest note. After calculating the wavelength and comparing it to the pitch of each tuning fork, students discover the relationship between wavelength and pitch.