Learners review the properties of waves and solve problems using wave property equations.
After completing this tutorial, you will be able to complete the following:
Waves range from electromagnetic waves to mechanical waves. Electromagnetic waves encompass visible light, broadcast and cellular communications, and microwaves. Mechanical waves, or vibrations, are perceived as sound. The physics of waves is simplified by the fact that both electromagnetic waves and mechanical waves share properties that allow their behaviors and characteristics to be measured.
A wave has amplitude (A), measured as the height from the midline to the highest or lowest point. The distance from one point of a wave (e.g., a crest) to the next corresponding point (e.g., the next crest) is the wavelength . The wavelength is the length of one complete wave cycle. The number of complete wave cycles to pass a fixed point in a given period of time is the frequency (f) of the wave. Frequency is measured in cycles per second, or hertz (Hz). The time it takes for one complete wave cycle to pass a fixed point is the period (T). Therefore, period and frequency are inversely related (f = 1/T and T = 1/f).
Waves travel at a characteristic speed, or propagation velocity (v). For electromagnetic waves, the propagation velocity is always the speed of light (3 × 108 m/s). For mechanical waves, the propagation velocity depends on the medium through which the wave is traveling. The speed of sound waves through air is typically estimated as 340 m/s. Propagation velocity can be calculated as the product of frequency and wavelength (v = f). Because of the relationships among wavelength, frequency, period, and speed, any of these physical properties can be determined if one or more of the others are known.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Learners must understand and be able to explain wavelength and period concepts, including the concepts of wavelength, period, frequency, and propagation velocity.|
|Type of Tutorial||Problem Solving|
|Key Vocabulary||amplitude, electromagnetic waves, frequencies|