Shared by a middle school science teacher in New Jersey.
The Electromagnetic Spectrum & Waves
Sound Beats and Sine Waves
Listen to and see interference patterns produced by sound waves with similar frequencies. Test your ability to distinguish and match sounds as musicians do when they tune their instruments. Calculate the number of "sound beats" you will hear based on the frequency of each sound. [Note: Headphones are recommended for this Gizmo.]
Subtractive Colors
Move spots of yellow, cyan, and magenta pigment on a white surface. As the colors overlap, other colors can be seen due to color subtraction. The color of most things you see--such as cars, leaves, paintings, houses, and clothes--are due to color subtraction. The intensity of the cyan, magenta, and yellow can be adjusted, and the RGB value at any location can be measured.
Refraction
Determine the angle of refraction for a light beam moving from one medium to another. The angle of incidence and each index of refraction can be varied. Using the tools provided, the angle of refraction can be measured, and the wavelength and frequency of the waves in each substance can be compared as well.
Laser Reflection
Point a laser at a mirror and compare the angle of the incoming beam to the angle of reflection. A protractor can be used to measure the angles of incidence and reflection, and the angle of the mirror can be adjusted. A beam splitter can be used to split the beam. Both plane and irregular mirrors can be used.